Question: will SARS-CoV2 infected people develop immunity? Is cross protection possible?

Title: Cytokine Storm in COVID-19 patients transforms to a Cytokine Super Cyclone in patients with risk factors Content: The seventh human coronavirus SARS-CoV2 belongs to the cluster of extremely pathogenic coronaviruses like SARS-CoV and MERS-CoV, which are established to cause lower respiratory tract infection. The viral infection can be fatal as the disease advances to pneumonia followed by acute respiratory distress syndrome (ARDS). Increasingly higher cytokine concentration on account of over-stimulated immune response against the virus, or the ‘cytokine storm’, is the reason behind the manifestation of lethal clinical symptoms. In this article, we discuss the immune pathogenesis of cytokine storm and its relation with SARS-CoV2/COVID-19 risk factors. People with underlying risk factors are more susceptible to fatal complications of COVID-19 infection leading to poor clinical outcome. The increased pro-inflammatory immune status in patients with risk factors (diabetes, hypertension, cardiovascular disease, COPD) exacerbates the Cytokine-storm of COVID-19 to a Cytokine Super Cyclone. We also overviewed antiviral immune response provided by BCG vaccine involving the IL-1β, IL-6 and TNF-α secretion via ‘trained monocytes’, which confers early protection against SARS-CoV2.

Title: SARS Cov2 infection in a renal transplanted patients. A case report. Content: The clinical manifestation of COVID-19 can vary from an asymptomatic course to ARDS requiring invasive mechanical ventilation and extracorporeal membrane oxygenation. A kidney transplanted patient infected with SARS CoV2 infection showed a mild disease despite immune suppression. It is possible that Immunosuppression can "be protective" as the cytokine storm is an important factor in the disease story. Despite the good outcome reported in the present case report, is remains of vital importance the solid organ transplant patients use precautions in order to avoid the infection.

Title: Clinical exacerbation of SARS-CoV2 infection after fingolimod withdrawal Content: The role of disease-modifying therapies in patients with autoimmune disorders during SARS-CoV2 infection is controversial. Immunocompromised patients could have a more severe COVID-19 disease, due to the absence of an adequate immune response against the SARS-CoV-2. However, therapies that act on immune response could play a protective role by dampening the cytokine release syndrome. Fingolimod is a drug used for immune therapy in patients with Multiple Sclerosis (MS) through the sequestration of activated lymphocytes in the lymph nodes. We report the case of a 57-year-old man with relapsing-remitting MS treated with fingolimod that showed a reactivation of COVID-19 with signs of hyperinflammation syndrome after fingolimod withdrawal. Our case suggests that discontinuation of fingolimod during COVID-19 could imply a worsening of SARS-CoV2 infection. This article is protected by copyright. All rights reserved.

Title: Clinical exacerbation of SARS‐CoV2 infection after fingolimod withdrawal Content: The role of disease‐modifying therapies in patients with autoimmune disorders during SARS‐CoV2 infection is controversial. Immunocompromised patients could have a more severe COVID‐19 disease, due to the absence of an adequate immune response against the SARS‐CoV‐2. However, therapies that act on immune response could play a protective role by dampening the cytokine release syndrome. Fingolimod is a drug used for immune therapy in patients with Multiple Sclerosis (MS) through the sequestration of activated lymphocytes in the lymph nodes. We report the case of a 57‐year‐old man with relapsing‐remitting MS treated with fingolimod that showed a reactivation of COVID‐19 with signs of hyperinflammation syndrome after fingolimod withdrawal. Our case suggests that discontinuation of fingolimod during COVID‐19 could imply a worsening of SARS‐CoV2 infection. This article is protected by copyright. All rights reserved.

Title: Antibody Dependent Enhancement Due to Original Antigenic Sin and the Development of SARS Content: Human coronavirus (HCoV) is one of the most common causes of respiratory tract infections throughout the world. Two phenomena observed so far in the development of the SARS-CoV-2 pandemic deserve further attention. First, the relative absence of clinical signs of infections in children, second, the early appearance of IgG in certain patients. From the point of view of immune system physiology, such an early rise of specific IgG is expected in secondary immune responses when memory to a cross-reactive antigen is present, usually from an earlier infection with a coronavirus. It is actually typical for the immune system to respond, to what it already knows, a phenomenon that has been observed in many infections with closely related viruses and has been termed “original antigenic sin.” The question then arises whether such cross-reactive antibodies are protective or not against the new virus. The worst scenario would be when such cross-reactive memory antibodies to related coronaviruses would not only be non-protective but even enhance infection and the clinical course. Such a phenomenon of antibody dependent enhancement (ADE) has already been described in several viral infections. Thus, the development of IgG against SARS-CoV-2 in the course of COVID-19 might not be a simple sign of viral clearance and developing protection against the virus. On the contrary, due to cross-reaction to related coronavirus strains from earlier infections, in certain patients IgG might enhance clinical progression due to ADE. The patient's viral history of coronavirus infection might be crucial to the development of the current infection with SARS-CoV-2. Furthermore, it poses a note of caution when treating COVID-19 patients with convalescent sera.

Title: Antibody Dependent Enhancement Due to Original Antigenic Sin and the Development of SARS Content: Human coronavirus (HCoV) is one of the most common causes of respiratory tract infections throughout the world. Two phenomena observed so far in the development of the SARS-CoV-2 pandemic deserve further attention. First, the relative absence of clinical signs of infections in children, second, the early appearance of IgG in certain patients. From the point of view of immune system physiology, such an early rise of specific IgG is expected in secondary immune responses when memory to a cross-reactive antigen is present, usually from an earlier infection with a coronavirus. It is actually typical for the immune system to respond, to what it already knows, a phenomenon that has been observed in many infections with closely related viruses and has been termed "original antigenic sin." The question then arises whether such cross-reactive antibodies are protective or not against the new virus. The worst scenario would be when such cross-reactive memory antibodies to related coronaviruses would not only be non-protective but even enhance infection and the clinical course. Such a phenomenon of antibody dependent enhancement (ADE) has already been described in several viral infections. Thus, the development of IgG against SARS-CoV-2 in the course of COVID-19 might not be a simple sign of viral clearance and developing protection against the virus. On the contrary, due to cross-reaction to related coronavirus strains from earlier infections, in certain patients IgG might enhance clinical progression due to ADE. The patient's viral history of coronavirus infection might be crucial to the development of the current infection with SARS-CoV-2. Furthermore, it poses a note of caution when treating COVID-19 patients with convalescent sera.

Title: The case for Chronotherapy in COVID‐19 induced Acute Respiratory Distress Syndrome (ARDS). Content: COVID‐19, the disease resulting from infection by a novel coronavirus: SARS‐Cov2 that has rapidly spread since November 2019 leading to a global pandemic. SARS‐Cov2 has infected over 4 million people and caused over 290,000 deaths worldwide. Although most cases are mild, a subset of patients develop a severe and atypical presentation of Acute Respiratory Distress Syndrome (ARDS) that is characterised by a cytokine release storm (CRS). Paradoxically, treatment with anti‐inflammatory agents and immune regulators has been associated with worsening of ARDS. We hypothesize that the intrinsic circadian clock of the lung and the immune system may regulate individual components of CRS and thus chronotherapy may be used to effectively manage ARDS in COVID‐19 patients.

Title: The case for chronotherapy in Covid-19-induced acute respiratory distress syndrome Content: Coronavirus disease 2019 (COVID-19), the disease resulting from infection by a novel coronavirus, SARS-Cov2, has rapidly spread since November 2019 leading to a global pandemic. SARS-Cov2 has infected over four million people and caused over 290,000 deaths worldwide. Although most cases are mild, a subset of patients develop a severe and atypical presentation of acute respiratory distress syndrome (ARDS) that is characterised by a cytokine release storm (CRS). Paradoxically, treatment with anti-inflammatory agents and immune regulators has been associated with worsening of ARDS. We hypothesize that the intrinsic circadian clock of the lung and the immune system may regulate individual components of CRS, and thus, chronotherapy may be used to effectively manage ARDS in COVID-19 patients.

Title: New IgM seroconversion and positive RT‐PCR test after exposure to the virus in recovered COVID‐19 patient Content: To date, understanding whether acquired immunity and presence of anti SARS‐Cov2 antibodies protects against reinfection is one the most important focus of the scientific community [1‐2]. Several studies suggest that acquired immunity may protect upon further exposure to SARS‐COV2 [3‐6]. Contrary to this picture, we describe a case of a patient recovered from COVID‐19 pneumonia with positive serology, followed up by 6 negative nasopharyngeal swab‐PCR tests performed along 1 month, who later on, after exposure to the virus, presented another positive RT‐PCR test and a second IgM seroconversion. This report opens up several possible interpretations. This article is protected by copyright. All rights reserved.

Title: COVID‐19 is milder in children possibly due to cross immunity Content: It has been unclear why the new severe acute respiratory syndrome coronavirus (sars‐CoV‐2) hits a small minority hard, while the vast majority of children appear to be protected and develop mild or no disease (1,2). The editorial by Brodin suggests some possible mechanisms why it is so (1). I would like to emphasize the significance of cross immunity due to previous exposure to seasonal coronavirus; it may be a plausible explanation for why children appear to be protected (2,3).

Title: Revisión Narrativa Sobre La Respuesta Inmunitaria Frente A Coronavirus: Descripción General, Aplicabilidad Para Sars-Cov2 E Implicaciones Terapéuticas Content: Abstract The new coronavirus (SARS-CoV2) that causes a severe acute respiratory syndrome emerged in Wuhan, China, in December 2019. It produces the aforementioned disease due to coronavirus 2019 (COVID-19), and has led to a declaration of a world public health emergency by the World Health Organisation. This new SARS-CoV2 virus could share characteristics and an immune response similar to those described for other coronavirus. Given its activity on the interferon pathway, and the manner in which it dysregulates innate immunity, the use of treatments directed at modulating or containing this could be of interest. A narrative review was made of the current evidence about immunity against coronavirus and it applicability to SARS-CoV2. The physiopathogenesis is also described, along with the underlying leucocyte activity, with the intention of clarifying the possible usefulness of inflammatory biomarkers and the development of personalised treatments.

Title: Virtual screening-driven drug discovery of SARS-CoV2 enzyme inhibitors targeting viral attachment, replication, post-translational modification and host immunity evasion infection mechanisms Content: The novel coronavirus SARS-CoV2, the causative agent of the pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide necessitated the discovery of new substances for anti-COVID-19 drug development. With the aid of bioinformatics and computational modelling, ninety seven antiviral secondary metabolites from fungi were docked onto five SARS-CoV2 enzymes involved in viral attachment, replication, post-translational modification, and host immunity evasion infection mechanisms followed by molecular dynamics simulation and in silico ADMET prediction (absorption, distribution, metabolism, excretion and toxicity) of the hit compounds. Thus, three fumiquinazoline alkaloids scedapin C (15), quinadoline B (19) and norquinadoline A (20), the polyketide isochaetochromin D1 (8), and the terpenoid 11a-dehydroxyisoterreulactone A (11) exhibited high binding affinities on the target proteins, papain-like protease (PLpro), chymotrypsin-like protease (3CLpro), RNA-directed RNA polymerase (RdRp), non-structural protein 15 (nsp15), and the spike binding domain to GRP78. Molecular dynamics simulation was performed to optimize the interaction and investigate the stability of the top-scoring ligands in complex with the five target proteins. All tested complexes were found to have dynamic stability. Of the five top-scoring metabolites, quinadoline B (19) was predicted to confer favorable ADMET values, high gastrointestinal absorptive probability and poor blood-brain barrier crossing capacities.Communicated by Ramaswamy H. Sarma.

Title: Severe acute respiratory syndrome vaccine development: experiences of vaccination against avian infectious bronchitis coronavirus. Content: Vaccines against infectious bronchitis of chickens (Gallus gallus domesticus) have arguably been the most successful, and certainly the most widely used, of vaccines for diseases caused by coronaviruses, the others being against bovine, canine, feline and porcine coronaviruses. Infectious bronchitis virus (IBV), together with the genetically related coronaviruses of turkey (Meleagris gallopovo) and ring-necked pheasant (Phasianus colchicus), is a group 3 coronavirus, severe acute respiratory syndrome (SARS) coronavirus being tentatively in group 4, the other known mammalian coronaviruses being in groups 1 and 2. IBV replicates not only in respiratory tissues (including the nose, trachea, lungs and airsacs, causing respiratory disease), but also in the kidney (associated with minor or major nephritis), oviduct, and in many parts of the alimentary tract--the oesophagus, proventriculus, duodenum, jejunum, bursa of Fabricius, caecal tonsils (near the distal end of the tract), rectum and cloaca (the common opening for release of eggs and faeces), usually without clinical effects. The virus can persist, being re-excreted at the onset of egg laying (4 to 5 months of age), believed to be a consequence of the stress of coming into lay. Genetic lines of chickens differ in the extent to which IBV causes mortality in chicks, and in respect of clearance of the virus after the acute phase. Live attenuated (by passage in chicken embryonated eggs) IBV strains were introduced as vaccines in the 1950s, followed a couple of decades later by inactivated vaccines for boosting protection in egg-laying birds. Live vaccines are usually applied to meat-type chickens at 1 day of age. In experimental situations this can result in sterile immunity when challenged by virulent homologous virus. Although 100% of chickens may be protected (against clinical signs and loss of ciliary activity in trachea), sometimes 10% of vaccinated chicks do not respond with a protective immune response. Protection is short lived, the start of the decline being apparent 9 weeks after vaccination with vaccines based on highly attenuated strains. IBV exists as scores of serotypes (defined by the neutralization test), cross-protection often being poor. Consequently, chickens may be re-vaccinated, with the same or another serotype, two or three weeks later. Single applications of inactivated virus has generally led to protection of <50% of chickens. Two applications have led to 90 to 100% protection in some reports, but remaining below 50% in others. In practice in the field, inactivated vaccines are used in laying birds that have previously been primed with two or three live attenuated virus vaccinations. This increases protection of the laying birds against egg production losses and induces a sustained level of serum antibody, which is passed to progeny. The large spike glycoprotein (S) comprises a carboxy-terminal S2 subunit (approximately 625 amino acid residues), which anchors S in the virus envelope, and an amino-terminal S1 subunit (approximately 520 residues), believed to largely form the distal bulbous part of S. The S1 subunit (purified from IBV virus, expressed using baculovirus or expressed in birds from a fowlpoxvirus vector) induced virus neutralizing antibody. Although protective immune responses were induced, multiple inoculations were required and the percentage of protected chickens was too low (<50%) for commercial application. Remarkably, expression of S1 in birds using a non-pathogenic fowl adenovirus vector induced protection in 90% and 100% of chickens in two experiments. Differences of as little as 5% between the S1 sequences can result in poor cross-protection. Differences in S1 of 2 to 3% (10 to 15 amino acids) can change serotype, suggesting that a small number of epitopes are immunodominant with respect to neutralizing antibody. Initial studies of the role of the IBV nucleocapsid protein (N) in immunity suggested that immunization with bacterially expressed N, while not inducing protection directly, improved the induction of protection by a subsequent inoculation with inactivated IBV. In another study, two intramuscular immunizations of a plasmid expressing N induced protective immunity. The basis of immunity to IBV is not well understood. Serum antibody levels do not correlate with protection, although local antibody is believed to play a role. Adoptive transfer of IBV-infection-induced alphabeta T cells bearing CD8 antigen protected chicks from challenge infection. In conclusion, live attenuated IBV vaccines induce good, although short-lived, protection against homologous challenge, although a minority of individuals may respond poorly. Inactivated IBV vaccines are insufficiently efficacious when applied only once and in the absence of priming by live vaccine. Two applications of inactivated IBV are much more efficacious, although this is not a commercially viable proposition in the poultry industry. However, the cost and logistics of multiple application of a SARS inactivated vaccine would be more acceptable for the protection of human populations, especially if limited to targeted groups (e.g. health care workers and high-risk contacts). Application of a SARS vaccine is perhaps best limited to a minimal number of targeted individuals who can be monitored, as some vaccinated persons might, if infected by SARS coronavirus, become asymptomatic excretors of virus, thereby posing a risk to non-vaccinated people. Looking further into the future, the high efficacy of the fowl adenovirus vector expressing the IBV S1 subunit provides optimism for a live SARS vaccine, if that were deemed to be necessary, with the possibility of including the N protein gene.

Title: Severe acute respiratory syndrome vaccine development: experiences of vaccination against avian infectious bronchitis coronavirus Content: Vaccines against infectious bronchitis of chickens (Gallus gallus domesticus) have arguably been the most successful, and certainly the most widely used, of vaccines for diseases caused by coronaviruses, the others being against bovine, canine, feline and porcine coronaviruses. Infectious bronchitis virus (IBV), together with the genetically related coronaviruses of turkey (Meleagris gallopavo) and ring-necked pheasant (Phasianus colchicus), is a group 3 coronavirus, Severe acute respiratory syndrome (SARS) coronavirus being tentatively in group 4, the other known mammalian coronaviruses being in groups 1 and 2. IBV replicates not only in respiratory tissues (including the nose, trachea, lungs and airsacs, causing respiratory disease), but also in the kidney (associated with minor or major nephritis), oviduct, and in many parts of the alimentary tract—the oesophagus, proventriculus, duodenum, jejunum, bursa of Fabricius, caecal tonsils, rectum and cloaca, usually without clinical effects. The virus can persist, being re-excreted at the onset of egg laying (4 to 5 months of age), believed to be a consequence of the stress of coming into lay. Genetic lines of chickens differ in the extent to which IBV causes mortality in chicks, and in respect of clearance of the virus after the acute phase. Live attenuated (by passage in chicken embryonated eggs) IBV strains were introduced as vaccines in the 1950s, followed a couple of decades later by inactivated vaccines for boosting protection in egg-laying birds. Live vaccines are usually applied to meat-type chickens at 1 day of age. In experimental situations this can result in sterile immunity when challenged by virulent homologous virus. Although 100% of chickens may be protected (against clinical signs and loss of ciliary activity in trachea), sometimes 10% of vaccinated chicks may not respond with a protective immune response. Protection is short lived, the start of the decline being apparent 9 weeks after vaccination with vaccines based on highly attenuated strains. IBV exists as scores of serotypes (defined by the neutralization test), cross-protection often being poor. Consequently, chickens may be re-vaccinated, with the same or another serotype, two or three weeks later. Single applications of inactivated virus has generally led to protection of <50% of chickens. Two applications have led to 90 to 100% protection in some reports, but remaining below 50% in others. In practice in the field, inactivated vaccines are used in laying birds that have previously been primed with two or three live attenuated virus vaccinations. This increases protection of the laying birds against egg production losses and induces a sustained level of serum antibody, which is passed to progeny. The large spike glycoprotein (S) comprises a carboxy-terminal S2 subunit (approximately 625 amino acid residues), which anchors S in the virus envelope, and an amino-terminal S1 subunit (approximately 520 residues), believed to largely form the distal bulbous part of S. The S1 subunit (purified from IBV virus, expressed using baculovirus or expressed in birds from a fowlpoxvirus vector) induced virus neutralizing antibody. Although protective immune responses were induced, multiple inoculations were required and the percentage of protected chickens was too low (<50%) for commercial application. Remarkably, expression of S1 in birds using a non-pathogenic fowl adenovirus vector induced protection in 90% and 100% of chickens in two experiments. Differences of as little as 5% between the S1 sequences can result in poor cross-protection. Differences in S1 of 2 to 3% (10 to 15 amino acids) can change serotype, suggesting that a small number of epitopes are immunodominant with respect to neutralizing antibody. Initial studies of the role of the IBV nucleocapsid protein (N) in immunity suggested that immunization with bacterially expressed N, while not inducing protection directly, improved the induction of protection by a subsequent inoculation with inactivated IBV. In another study, two intramuscular immunizations of a plasmid expressing N induced protective immunity. The basis of immunity to IBV is not well understood. Serum antibody levels do not correlate with protection, although local antibody is believed to play a role. Adoptive transfer of IBV-infection-induced αβ T cells bearing CD8 antigen protected chicks from challenge infection. In conclusion, live attenuated IBV vaccines induce good, although short-lived, protection against homologous challenge, although a minority of individuals may respond poorly. Inactivated IBV vaccines are insufficiently efficacious when applied only once and in the absence of priming by live vaccine. Two applications of inactivated IBV are much more efficacious, although this is not a commercially viable proposition in the poultry industry. However, the cost and logistics of multiple application of a SARS inactivated vaccine would be more acceptable for the protection of human populations, especially if limited to targeted groups (e.g. health care workers and high-risk contacts). Application of a SARS vaccine is perhaps best limited to a minimal number of targeted individuals who can be monitored, as some vaccinated persons might, if infected by SARS coronavirus, become asymptomatic excretors of virus, thereby posing a risk to non-vaccinated people. Looking further into the future, the high efficacy of the fowl adenovirus vector expressing the IBV S1 subunit provides optimism for a live SARS vaccine, if that were deemed to be necessary, with the possibility of including the N protein gene.

Title: Ebselen as a highly active inhibitor of PLProCoV2 Content: Since December 2019 a novel a coronavirus identified as SARS-CoV-2 or COV2 has been spreading around the world. On the 16th of May around 4.5 million people got infected and over 300,000 died due to the infection of COV2. The effective treatment remains a challenge. Targeted therapeutics are still under investigation. The papain-like protease (PLPro) from the human SARS-CoV-2 coronavirus is a cysteine protease that plays a critical role in virus replication. Its activity is required to process the viral polyprotein into functional, mature subunits. Moreover, COV2 uses this enzyme to modulate the host’s immune system to its own benefit. Therefore, it represents a highly promising target for the development of antiviral drugs. In this work, we discovered that ebselen, a synthetic organoselenium drug molecule with anti-inflammatory, anti-oxidant and cytoprotective activity in mammalian cells and cytotoxicity in lower organisms, is a highly active inhibitor of PLProCoV2. We proved that ebselen is a covalent, fast-binding inhibitor of PLProCoV2 exhibiting a low micromolar potency. Furthermore, we identified a difference between PLPro from SARS-CoV-1 (the corona virus which caused the 2002–2004 outbreak, SARS) and SARS-CoV-2 that allows to explain the difference in dynamics of the replication, and, thus, the disease progression. Namely, we present that they show differences in the binding affinity of substrates that we observed through kinetics and molecular docking studies. Using a novel Approximate Bayesian Computation method we were able to find kinetic constants for both enzymes. Molecular modeling study on the structure of the active site and binding mode of the ebselen with SARS and COV2 showed also significant differences that could explain our observation that ebselen is less active and slower bounding with SARS than COV2. In conclusion, we show that ebselen inhibits the activity of the essential viral enzyme papain-like protease (PLpro) from SARS-COV-2 in low micromolar range.

Title: Guidelines for the management of surgical departments in non-uniform hospitals during the COVID-19 pandemic. Content: In the last several weeks we have been witnessing the exponentially progressing pandemic SARS-CoV-2 coronavirus. As the number of people infected with SARS-CoV2 escalates, the problem of surgical management of patients requiring urgent surgery is increasing. Patients infected with SARS-CoV2 virus but with negative test results will appear in general hospitals and may pose a risk to other patients and hospital staff. Health care workers constitutes nearly 17% of infected population in Poland, therefore early identification of infected people becomes a priority to protect human resources and to ensure continuity of the access to a surgical care. Both surgical operations, and endoscopic procedures are considered as interventions with an increased risk of infection. Therefore, determining the algorithm becomes crucial for qualifying patients for surgical treatment, but also to stratify the risk of personnel being infected during surgery and to adequately protect staff. Each hospital should be logistically prepared for the need to perform urgent surgery on a patient with suspected or confirmed infection, including personal protective equipment. Limited availability of the equipment, working under pressure and staff shortages in addition to a highly contagious pathogen necessitate a pragmatic management of human resources in health care. Instant synchronized action is needed, and clear uniform guidelines are essential for the healthcare system to provide citizens with the necessary surgical care while protecting both patients, and staff. This document presents current recommendations regarding surgery during the COVID-19 pandemic in Poland.

Title: Guidelines for the management of surgical departments in non-uniform hospitals during the COVID-19 pandemic Content: In the last several weeks we have been witnessing the exponentially progressing pandemic SARS-CoV-2 coronavirus. As the number of people infected with SARS-CoV2 escalates, the problem of surgical management of patients requiring urgent surgery is increasing. Patients infected with SARS-CoV2 virus but with negative test results will appear in general hospitals and may pose a risk to other patients and hospital staff. Health care workers constitutes nearly 17% of infected population in Poland, therefore early identification of infected people becomes a priority to protect human resources and to ensure continuity of the access to a surgical care. Both surgical operations, and endoscopic procedures are considered as interventions with an increased risk of infection. Therefore, determining the algorithm becomes crucial for qualifying patients for surgical treatment, but also to stratify the risk of personnel being infected during surgery and to adequately protect staff. Each hospital should be logistically prepared for the need to perform urgent surgery on a patient with suspected or confirmed infection, including personal protective equipment. Limited availability of the equipment, working under pressure and staff shortages in addition to a highly contagious pathogen necessitate a pragmatic management of human resources in health care. Instant synchronized action is needed, and clear uniform guidelines are essential for the healthcare system to provide citizens with the necessary surgical care while protecting both patients, and staff. This document presents current recommendations regarding surgery during the COVID-19 pandemic in Poland.

Title: Global cataloguing of variations in untranslated regions of viral genome and prediction of key host RNA binding protein-microRNA interactions modulating genome stability in SARS-CoV2 Content: Background The world is going through the critical phase of COVID-19 pandemic, caused by human coronavirus, SARS-CoV2. Worldwide concerted effort to identify viral genomic changes across different sub-types has identified several strong changes in the coding region. However, there have not been many studies focusing on the variations in the 5’ and 3’ untranslated regions and their consequences. Considering the possible importance of these regions in host mediated regulation of viral RNA genome, we wanted to explore the phenomenon. Methods To have an idea of the global changes in 5’ and 3’-UTR sequences, we downloaded 8595 complete and high-coverage SARS-CoV2 genome sequence information from human host in FASTA format from Global Initiative on Sharing All Influenza Data (GISAID) from 15 different geographical regions. Next, we aligned them using Clustal Omega software and investigated the UTR variants. We also looked at the putative host RNA binding protein (RBP) and microRNA binding sites in these regions by ‘RBPmap’ and ‘RNA22 v2’ respectively. Expression status of selected RBPs and microRNAs were checked in lungs tissue. Results We identified 28 unique variants in SARS-CoV2 UTR region based on a minimum variant percentage cut-off of 0.5. Along with 241C>T change the important 5’-UTR change identified was 187A>G, while 29734G>C, 29742G>A/T and 29774C>T were the most familiar variants of 3’UTR among most of the continents. Furthermore, we found that despite of the variations in the UTR regions, binding of host RBP to them remains mostly unaltered, which further influenced the functioning of specific miRNAs. Conclusion Our results, shows for the first time in SARS-Cov2 infection, a possible cross-talk between host RBPs-miRNAs and viral UTR variants, which ultimately could explain the mechanism of escaping host RNA decay machinery by the virus. The knowledge might be helpful in developing anti-viral compounds in future.

Title: Potential Therapeutic Targeting of Coronavirus Spike Glycoprotein Priming Content: Processing of certain viral proteins and bacterial toxins by host serine proteases is a frequent and critical step in virulence. The coronavirus spike glycoprotein contains three (S1, S2, and S2′) cleavage sites that are processed by human host proteases. The exact nature of these cleavage sites, and their respective processing proteases, can determine whether the virus can cross species and the level of pathogenicity. Recent comparisons of the genomes of the highly pathogenic SARS-CoV2 and MERS-CoV, with less pathogenic strains (e.g., Bat-RaTG13, the bat homologue of SARS-CoV2) identified possible mutations in the receptor binding domain and in the S1 and S2′ cleavage sites of their spike glycoprotein. However, there remains some confusion on the relative roles of the possible serine proteases involved for priming. Using anthrax toxin as a model system, we show that in vivo inhibition of priming by pan-active serine protease inhibitors can be effective at suppressing toxicity. Hence, our studies should encourage further efforts in developing either pan-serine protease inhibitors or inhibitor cocktails to target SARS-CoV2 and potentially ward off future pandemics that could develop because of additional mutations in the S-protein priming sequence in coronaviruses.

Title: Potential Therapeutic Targeting of Coronavirus Spike Glycoprotein Priming Content: Processing of certain viral proteins and bacterial toxins by host serine proteases is a frequent and critical step in virulence. The coronavirus spike glycoprotein contains three (S1, S2, and S2') cleavage sites that are processed by human host proteases. The exact nature of these cleavage sites, and their respective processing proteases, can determine whether the virus can cross species and the level of pathogenicity. Recent comparisons of the genomes of the highly pathogenic SARS-CoV2 and MERS-CoV, with less pathogenic strains (e.g., Bat-RaTG13, the bat homologue of SARS-CoV2) identified possible mutations in the receptor binding domain and in the S1 and S2' cleavage sites of their spike glycoprotein. However, there remains some confusion on the relative roles of the possible serine proteases involved for priming. Using anthrax toxin as a model system, we show that in vivo inhibition of priming by pan-active serine protease inhibitors can be effective at suppressing toxicity. Hence, our studies should encourage further efforts in developing either pan-serine protease inhibitors or inhibitor cocktails to target SARS-CoV2 and potentially ward off future pandemics that could develop because of additional mutations in the S-protein priming sequence in coronaviruses.

Title: Virtual screening-driven drug discovery of SARS-CoV2 enzyme inhibitors targeting viral attachment, replication, post-translational modification and host immunity evasion infection mechanisms Content: The novel coronavirus SARS-CoV2, the causative agent of the pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide necessitated the discovery of new substances for anti-COVID-19 drug development. With the aid of bioinformatics and computational modelling, ninety seven antiviral secondary metabolites from fungi were docked onto five SARS-CoV2 enzymes involved in viral attachment, replication, post-translational modification, and host immunity evasion infection mechanisms followed by molecular dynamics simulation and in silico ADMET prediction (absorption, distribution, metabolism, excretion and toxicity) of the hit compounds. Thus, three fumiquinazoline alkaloids scedapin C (15), quinadoline B (19) and norquinadoline A (20), the polyketide isochaetochromin D1 (8), and the terpenoid 11a-dehydroxyisoterreulactone A (11) exhibited high binding affinities on the target proteins, papain-like protease (PLpro), chymotrypsin-like protease (3CLpro), RNA-directed RNA polymerase (RdRp), non-structural protein 15 (nsp15), and the spike binding domain to GRP78. Molecular dynamics simulation was performed to optimize the interaction and investigate the stability of the top-scoring ligands in complex with the five target proteins. All tested complexes were found to have dynamic stability. Of the five top-scoring metabolites, quinadoline B (19) was predicted to confer favorable ADMET values, high gastrointestinal absorptive probability and poor blood-brain barrier crossing capacities. Communicated by Ramaswamy H. Sarma

Title: A perspective on potential antibody-dependent enhancement of SARS-CoV-2. Content: The possibility of antibody-dependent enhancement (ADE) of disease is a general concern for the development of vaccines and antibody therapies because the mechanisms that underlie antibody protection have the theoretical potential to amplify viral infections or trigger immunopathology. Observations relevant to the risks of ADE of disease require careful review at this critical point in the SARS-CoV-2 pandemic. At present, no clinical findings, immunologic assays or biomarkers are known to differentiate any severe viral infection from immune-enhanced disease, whether by antibodies, T cells or intrinsic host responses. In vitro systems and animal models do not predict the risk of ADE of disease, in part because protective and potentially detrimental antibody-mediated mechanisms are the same, and designing animal models depends on understanding how antiviral host responses may become harmful in people. The implications of our lack of knowledge are twofold. First, comprehensive studies are urgently needed to define clinical correlates of protective immunity against SARS-CoV-2. Second, since we cannot predict ADE of disease reliably after either vaccination or treatment with antibodies, regardless of what virus is the causative agent, it will be essential to depend on careful analysis of safety in humans as immune interventions for COVID-19 disease move forward.

Title: Immunization with the receptor–binding domain of SARS-CoV-2 elicits antibodies cross-neutralizing SARS-CoV-2 and SARS-CoV without antibody-dependent enhancement Content: Recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic. Currently, there is no vaccine available for preventing SARS-CoV-2 infection. Like closely related severe acute respiratory syndrome coronavirus (SARS-CoV), SARS-CoV-2 also uses its receptor-binding domain (RBD) on the spike (S) protein to engage the host receptor, human angiotensin-converting enzyme 2 (ACE2), facilitating subsequent viral entry. Here we report the immunogenicity and vaccine potential of SARS-CoV-2 RBD (SARS2-RBD)-based recombinant proteins. Immunization with SARS2-RBD recombinant proteins potently induced a multi-functional antibody response in mice. The resulting antisera could efficiently block the interaction between SARS2-RBD and ACE2, inhibit S-mediated cell-cell fusion, and neutralize both SARS-CoV-2 pseudovirus entry and authentic SARS-CoV-2 infection. In addition, the anti-RBD sera also exhibited cross binding, ACE2-blockade, and neutralization effects towards SARS-CoV. More importantly, we found that the anti-RBD sera did not promote antibody-dependent enhancement of either SARS-CoV-2 pseudovirus entry or authentic virus infection of Fc receptor-bearing cells. These findings provide a solid foundation for developing RBD-based subunit vaccines for SARS-CoV2.

Title: SARS-CoV-2 assays to detect functional antibody responses that block ACE2 recognition in vaccinated animals and infected patients Content: SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has caused a global pandemic of COVID-19 resulting in cases of mild to severe respiratory distress and significant mortality. The global outbreak of this novel coronavirus has now infected >8 million people worldwide with >2 million cases in the US (June 17th, 2020). There is an urgent need for vaccines and therapeutics to combat the spread of this coronavirus. Similarly, the development of diagnostic and research tools to determine infection and vaccine efficacy are critically needed. Molecular assays have been developed to determine viral genetic material present in patients. Serological assays have been developed to determine humoral responses to the spike protein or receptor binding domain (RBD). Detection of functional antibodies can be accomplished through neutralization of live SARS-CoV2 virus, but requires significant expertise, an infectible stable cell line, a specialized BioSafety Level 3 (BSL-3) facility. As large numbers of people return from quarantine, it is critical to have rapid diagnostics that can be widely adopted and employed to assess functional antibody levels in the returning workforce. This type of surrogate neutralization diagnostic can also be used to assess humoral immune responses induced in patients from the large number of vaccine and immunotherapy trials currently on-going. Here we describe a rapid serological diagnostic assay for determining antibody receptor blocking and demonstrate the broad utility of the assay by measuring the antibody functionality of sera from small animals and non-human primates immunized with an experimental SARS-CoV-2 vaccine and using sera from infected patients.

Title: Structural Similarity of SARS-CoV2 Mpro and HCV NS3/4A Proteases Suggests New Approaches for Identifying Existing Drugs Useful as COVID-19 Therapeutics. Content: During the current COVID-19 pandemic more than 160,000 people have died worldwide as of mid-April 2020, and the global economy has been crippled. Effective control of the SARS-CoV2 virus that causes the COVID-19 pandemic requires both vaccines and antivirals. Antivirals are particularly crucial to treat infected people during the period of time that an effective vaccine is being developed and deployed. Because the development of specific antiviral drugs can take a considerable length of time, an important approach is to identify existing drugs already approved for use in humans which could be repurposed as COVID-19 therapeutics. Here we focus on antivirals directed against the SARS-CoV2 Mpro protease, which is required for virus replication. A structural similarity search showed that the Hepatitis C virus (HCV) NS3/4A protease has a striking three-dimensional structural similarity to the SARS-CoV2 Mpro protease, particularly in the arrangement of key active site residues. We used virtual docking predictions to assess the hypothesis that existing drugs already approved for human use or clinical testing that are directed at the HCV NS3/4A protease might fit well into the active-site cleft of the SARS-CoV2 protease (Mpro). AutoDock docking scores for 12 HCV protease inhibitors and 9 HIV-1 protease inhibitors were determined and compared to the docking scores for an α-ketoamide inhibitor of Mpro, which has recently been shown to inhibit SARS-CoV2 virus replication in cell culture. We identified eight HCV protease inhibitors that bound to the Mpro active site with higher docking scores than the α-ketoamide inhibitor, suggesting that these protease inhibitors may effectively bind to the Mpro active site. These results provide the rationale for us to test the identified HCV protease inhibitors as inhibitors of the SARS-CoV2 protease, and as inhibitors of SARS-CoV2 virus replication. Subsequently these repurposed drugs could be evaluated as COVID-19 therapeutics.

Title: Challenges in Dengue Vaccines Development: Pre-existing Infections and Cross-Reactivity Content: Dengue is one of the most frequently transmitted mosquito-borne diseases in the world, which creates a significant public health concern globally, especially in tropical and subtropical countries. It is estimated that more than 390 million people are infected with dengue virus each year and around 96 million develop clinical pathologies. Dengue infections are not only a health problem but also a substantial economic burden. To date, there are no effective antiviral therapies and there is only one licensed dengue vaccine that only demonstrated protection in the seropositive (Immune), naturally infected with dengue, but not dengue seronegative (Naïve) vaccines. In this review, we address several immune components and their interplay with the dengue virus. Additionally, we summarize the literature pertaining to current dengue vaccine development and advances. Moreover, we review some of the factors affecting vaccine responses, such as the pre-vaccination environment, and provide an overview of the significant challenges that face the development of an efficient/protective dengue vaccine including the presence of multiple serotypes, antibody-dependent enhancement (ADE), as well as cross-reactivity with other flaviviruses. Finally, we discuss targeting T follicular helper cells (Tfh), a significant cell population that is essential for the production of high-affinity antibodies, which might be one of the elements needed to be specifically targeted to enhance vaccine precision to dengue regardless of dengue serostatus.

Title: COVID-19: Immunology and treatment options Content: The novel coronavirus SARS-CoV2 causes COVID-19, a pandemic threatening millions. As protective immunity does not exist in humans and the virus is capable of escaping innate immune responses, it can proliferate, unhindered, in primarily infected tissues. Subsequent cell death results in the release of virus particles and intracellular components to the extracellular space, which result in immune cell recruitment, the generation of immune complexes and associated damage. Infection of monocytes/macrophages and/or recruitment of uninfected immune cells can result in massive inflammatory responses later in the disease. Uncontrolled production of pro-inflammatory mediators contributes to ARDS and cytokine storm syndrome. Antiviral agents and immune modulating treatments are currently being trialled. Understanding immune evasion strategies of SARS-CoV2 and the resulting delayed massive immune response will result in the identification of biomarkers that predict outcomes as well as phenotype and disease stage specific treatments that will likely include both antiviral and immune modulating agents.

Title: COVID-19: Immunology and treatment options Content: Abstract The novel coronavirus SARS-CoV2 causes COVID-19, a pandemic threatening millions. As protective immunity does not exist in humans and the virus is capable of escaping innate immune responses, it can proliferate, unhindered, in primarily infected tissues. Subsequent cell death results in the release of virus particles and intracellular components to the extracellular space, which result in immune cell recruitment, the generation of immune complexes and associated damage. Infection of monocytes/macrophages and/or recruitment of uninfected immune cells can result in massive inflammatory responses later in the disease. Uncontrolled production of pro-inflammatory mediators contributes to ARDS and cytokine storm syndrome. Antiviral agents and immune modulating treatments are currently being trialled. Understanding immune evasion strategies of SARS-CoV2 and the resulting delayed massive immune response will result in the identification of biomarkers that predict outcomes as well as phenotype and disease stage specific treatments that will likely include both antiviral and immune modulating agents.

Title: Herd immunity or suppression strategy to combat COVID-19. Content: Some months ago, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan, China, and spread rapidly around the world. Some states, such as the Netherlands, Germany, Great Britain, Sweden and the USA initially focused on keeping the restrictions for economy and society as low as possible. The responsible authorities were of the opinion - and still are e.g. in Sweden - that it is sufficient enough to protect particularly vulnerable persons such as the elderly or people with pre-existing conditions. The idea behind this is that as soon as 60 to 70 percent of the population is infected with a pathogen, a so-called "herd immunity" has developed. However, the increasing numbers of deaths and modelling studies showed the expected overload of the hospitals. Therefore, most countries decided for a temporary lockdown with the exception of Sweden.Based on the number of the total population, three times more people died from COVID-19 in Sweden (2679 deaths per 10 million inhabitants) compared to Germany (6848 deaths per 80 million inhabitants). The comparison Sweden versus Taiwan is even worse because 1072 times more people died in Sweden based on the number of the population (6 deaths per 24 million inhabitants).In the face of the lack of an antiviral treatment and the lack of a protective vaccine one must state Taiwan has made the best out of the pandemic situation whereas Sweden failed completely.

Title: Herd immunity or suppression strategy to combat COVID-19 Content: Some months ago, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan, China, and spread rapidly around the world. Some states, such as the Netherlands, Germany, Great Britain, Sweden and the USA initially focused on keeping the restrictions for economy and society as low as possible. The responsible authorities were of the opinion - and still are e.g. in Sweden - that it is sufficient enough to protect particularly vulnerable persons such as the elderly or people with pre-existing conditions. The idea behind this is that as soon as 60 to 70 percent of the population is infected with a pathogen, a so-called "herd immunity" has developed. However, the increasing numbers of deaths and modelling studies showed the expected overload of the hospitals. Therefore, most countries decided for a temporary lockdown with the exception of Sweden.Based on the number of the total population, three times more people died from COVID-19 in Sweden (2679 deaths per 10 million inhabitants) compared to Germany (6848 deaths per 80 million inhabitants). The comparison Sweden versus Taiwan is even worse because 1072 times more people died in Sweden based on the number of the population (6 deaths per 24 million inhabitants).In the face of the lack of an antiviral treatment and the lack of a protective vaccine one must state Taiwan has made the best out of the pandemic situation whereas Sweden failed completely.

Title: Immunodominant viral peptides as determinants of cross-reactivity in the immune system – Can we develop wide spectrum viral vaccines? Content: Summary When we look back to Edward Jenner vaccination of a young man in 1796, we cannot help thinking that he was both lucky and crazy. Crazy because he decided to test in a human being a hypothesis based mainly in the traditional belief that people who had acquired cowpox from the udders of a cow were thereafter resistant to smallpox, a quite devastating disease, and lucky because (even considering that he did not know this at that time) he succeeded to induce protection against a pathogen through the induction of an immune response directed against a different agent. Not only was he able to protect the young man but he took the first step towards the development of a vast new field, vaccination. It is acceptable to say that Jenner was lucky because he succeeded in promoting protection against smallpox using a cowpox virus and this induction of protection in a cross-reactive way is believed to be quite rare. Nevertheless, more and more examples of cross-reactive immune responses are being described and we are beginning to admit that cross-reactivity is far more common and important than we used to think. Here we review cross-reactivity in the immune system and the plasticity of T cell recognition. Based on the existence of T cell receptor promiscuous recognition and cross-recognition of conserved viral immunodominant epitopes, we propose two approaches to develop wide spectrum viral vaccines. The first one is based on the identification, characterization, and cloning of immunodominant viral epitopes able to stimulate responses against different viruses. The produced peptides could then be purified and serve as a basis for vaccine therapies. A second strategy is based on the identification of conserved patterns in immunodominant viral peptides and the production of synthetic peptides containing the amino acid residues necessary for MHC anchoring and TCR contact. Although we are still far from a complete knowledge of the cross-reactivity phenomenon in the immune system, the analysis of immunodominant viral epitopes and the identification of particular “viral patterns” seems to be important steps towards the development of wide spectrum viral vaccines.

Title: SARS‐COV‐2 and infectivity: Possible increase in infectivity associated to integrin motif expression Content: SARS-COV2 represents the causal agent of a potentially fatal disease (COVID-19) that is actually of great global public health concern. SARS-COV2 has diffused throughout the world surprisingly fast demonstrating a far greater infectivity than previously known human coronaviruses and it is also responsible for an unusual high variety of symptoms in affected patients. This article is protected by copyright. All rights reserved.

Title: The kidney in COVID-19: protagonist or figurant? Content: The etiology of injury in COVID-19 patients is diverse and multifactorial. Autopsy and biopsy studies reveal, alongside podocyte and tubular cell anomalies, the presence of virion within the cells. Evidence suggests that, in addition to the direct cytopathic effect of SARS- CoV2 on the glomeruli and renal tubules, there is also the indirect effect of cell-mediated immunity, the cytokines storm and the cross-talk between organs with possible systemic effects of the disease. These mechanisms are interconnected and have profound therapeutic implications involving extracorporeal removal of inflammatory cytokines. Dialysis patients, and children, in particular, should be classified as "at high risk" of contracting the disease. Infections are one of the most frequent causes of death in children with chronic renal failure who undergo dialysis. The reasons for this particular susceptibility are to be found in the compromised immune system, secondary to chronic malnutrition, immunosuppressive therapy, and uremia, frequent contact with healthcare personnel and other patients attending the dialysis unit and in need of the presence of other family members during treatment.

Title: Can the protection be among us? Previous viral contacts and prevalent HLA alleles could be avoiding an even more disseminated COVID-19 pandemic. Content: Background: COVID-19 is bringing scenes of sci-fi movies into real life, and it seems to be far from over. Infected individuals exhibit variable severity, with no relation between the number of cases and mortality, suggesting the involvement of the populational genetic constitution and previous cross-reactive immune contacts in the individuals' disease outcome. Methods: A clustering approach was conducted to investigate the involvement of human MHC alleles with individuals' outcomes. HLA frequencies from affected countries were used to fuel the Hierarchical Clusterization Analysis. The formed groups were compared regarding their death rates. To prospect the T cell targets in SARS-CoV-2, and by consequence, the epitopes that are conferring cross-protection in the current pandemic, we modeled 3D structures of HLA-A*02:01 presenting immunogenic epitopes from SAR-CoV-1, recovered from Immune Epitope Database. These pMHC structures were also compared with models containing the corresponding SARS-CoV-2 epitope, with alphacoronavirus sequences, and with a panel of immunogenic pMHC structures contained in CrossTope. Findings: The combined use of HLA-B*07, HLA-B*44, HLA-DRB1*03, and HLADRB1*04 allowed the clustering of affected countries presenting similar death rates, based only on their allele frequencies. SARS-CoV HLA-A*02:01 epitopes were structurally investigated. It reveals molecular conservation between SARS-CoV-1 and SARS-CoV-2 peptides, enabling the use of formerly SARS-CoV-1 experimental epitopes to inspect actual targets that are conferring cross-protection. Alpha-CoVs and, impressively, viruses involved in human infections share fingerprints of immunogenicity with SARS-CoV peptides. Interpretation: Wide-scale HLA genotyping in COVID-19 patients shall improve prognosis prediction. Structural identification of previous triggers paves the way for herd immunity examination and wide spectrum vaccine development. Funding: This work was supported by the National Council for Scientific and Technological Development (CNPq) and National Council for the Improvement of Higher Education (CAPES) for their support

Title: A dissection of SARS-CoV2 with clinical implications (Review) Content: We are being confronted with the most consequential pandemic since the Spanish flu of 1918-1920 to the extent that never before have 4 billion people quarantined simultaneously; to address this global challenge we bring to the forefront the options for medical treatment and summarize SARS-CoV2 structure and functions, immune responses and known treatments. Based on literature and our own experience we propose new interventions, including the use of amiodarone, simvastatin, pioglitazone and curcumin. In mild infections (sore throat, cough) we advocate prompt local treatment for the naso-pharynx (inhalations; aerosols; nebulizers); for moderate to severe infections we propose a tried-and-true treatment: the combination of arginine and ascorbate, administered orally or intravenously. The material is organized in three sections: i) Clinical aspects of COVID-19; acute respiratory distress syndrome (ARDS); known treatments; ii) Structure and functions of SARS-CoV2 and proposed antiviral drugs; iii) The combination of arginine-ascorbate.

Title: SARS - CoV-2: Reasons of epidemiology of severe ill disease cases and therapeutic approach using trivalent vaccine (tetanus, diphtheria and Bordetella pertussis) Content: The novel coronavirus Covid-19 follows transmission route and clinical presentation of all community-acquired coronaviruses. Instead, the rate of transmission is significative higher, with a faster spread of the virus responsible of the worldwide outbreak and a significative higher mortality rate due to the development of a severe lung injury. Most noteworthy is the distribution of death rate among age groups. Children and younger people are almost protected from severe clinical presentation. Possible explanation of this phenomenon could be the ability of past vaccinations (especially tetanic, diphtheria toxoids and inactivated bacteria as pertussis) to stimulate immune system and to generate a scattered immunity against non-self antigens in transit, as coronaviruses and other community-circulating viruses and make immune system readier to develop specific immunity against Covid-19. The first support to this hypothesis is the distribution of mortality rate during historical pandemics ("Spanish flu" 1918, "Asian flu" 1956 and "the Hong Kong flu" 1968) among age groups before and after the introduction of vaccines. The immunological support to the hypothesis derives from recent studies about immunotherapy for malignancies, which propose the use of oncolytic vaccines combined with toxoids in order to exploit CD4 + memory T cell recall in supporting the ongoing anti-tumour response. According to this hypothesis vaccine formulations (tetanus, diphtheria, Bordetella pertussis) could be re-administrate after the first contact with Covid-19, better before the development of respiratory severe illness and of course before full-blown ARDS (Acute Respiratory Distress Syndrome). The CD4 + memory exploiting could help immune system to recall immunity of already know antigens against coronaviruses, avoiding or limiting "lung crash" until virus specific immunity develops and making it faster and prolonged. Finally, this administration could be helpful not only in already infected patients, but also before infection. In fact, people could have an immune system more ready when the contact with the Covid-19 will occur.

Title: SARS – CoV -2: reasons of epidemiology of severe ill disease cases and therapeutic approach using trivalent vaccine (tetanus, diphtheria and Bordetella pertussis) Content: Abstract The novel coronavirus COVID-19 follows transmission route and clinical presentation of all community-acquired coronaviruses. Instead, the rate of transmission is significative higher, with a faster spread of the virus responsible of the worldwide outbreak and a significative higher mortality rate due to the development of a severe lung injury. Most noteworthy is the distribution of death rate among age groups. Children and younger people are almost protected from severe clinical presentation. Possible explanation of this phenomenon could be the ability of past vaccinations (especially tetanic, diphtheria toxoids and inactivated bacteria as pertussis) to stimulate immune system and to generate a scattered immunity against non-self antigens in transit, as coronaviruses and other community-circulating viruses and make immune system readier to develop specific immunity against COVID-19. The first support to this hypothesis is the distribution of mortality rate during historical pandemics (“Spanish flu” 1918, “Asian flu” 1956 and “the Hong Kong flu” 1968) among age groups before and after the introduction of vaccines. The immunological support to the hypothesis derives from recent studies about immunotherapy for malignancies, which propose the use of oncolytic vaccines combined with toxoids in order to exploit CD4+ memory T cell recall in supporting the ongoing anti-tumour response. According to this hypothesis vaccine formulations (tetanus, diphtheria, Bordetella pertussis) could be re-administrate after the first contact with Covid-19, better before the development of respiratory severe illness and of course before full-blown ARDS (Acute Respiratory Distress Syndrome). The CD4+ memory exploiting could help immune system to recall immunity of already know antigens against coronaviruses, avoiding or limiting “lung crash” until virus specific immunity develops and making it faster and prolonged. Finally, this administration could be helpful not only in already infected patients, but also before infection. In fact, people could have an immune system more ready when the contact with the COVID-19 will occur.

Title: Respiratory virus-induced heterologous immunity: Part of the problem or part of the solution? Content: PURPOSE: To provide current knowledge on respiratory virus-induced heterologous immunity (HI) with a focus on humoral and cellular cross-reactivity. Adaptive heterologous immune responses have broad implications on infection, autoimmunity, allergy and transplant immunology. A better understanding of the mechanisms involved might ultimately open up possibilities for disease prevention, for example by vaccination. METHODS: A structured literature search was performed using Medline and PubMed to provide an overview of the current knowledge on respiratory-virus induced adaptive HI. RESULTS: In HI the immune response towards one antigen results in an alteration of the immune response towards a second antigen. We provide an overview of respiratory virus-induced HI, including viruses such as respiratory syncytial virus (RSV), rhinovirus (RV), coronavirus (CoV) and influenza virus (IV). We discuss T cell receptor (TCR) and humoral cross-reactivity as mechanisms of HI involving those respiratory viruses. Topics covered include HI between respiratory viruses as well as between respiratory viruses and other pathogens. Newly developed vaccines which have the potential to provide protection against multiple virus strains are also discussed. Furthermore, respiratory viruses have been implicated in the development of autoimmune diseases, such as narcolepsy, Guillain–Barré syndrome, type 1 diabetes or myocarditis. Finally, we discuss the role of respiratory viruses in asthma and the hygiene hypothesis, and review our recent findings on HI between IV and allergens, which leads to protection from experimental asthma. CONCLUSION: Respiratory-virus induced HI may have protective but also detrimental effects on the host. Respiratory viral infections contribute to asthma or autoimmune disease development, but on the other hand, a lack of microbial encounter is associated with an increasing number of allergic as well as autoimmune diseases. Future research might help identify the elements which determine a protective or detrimental outcome in HI-based mechanisms.

Title: Respiratory virus-induced heterologous immunity: Part of the problem or part of the solution? Content: PURPOSE: To provide current knowledge on respiratory virus-induced heterologous immunity (HI) with a focus on humoral and cellular cross-reactivity. Adaptive heterologous immune responses have broad implications on infection, autoimmunity, allergy and transplant immunology. A better understanding of the mechanisms involved might ultimately open up possibilities for disease prevention, for example by vaccination. METHODS: A structured literature search was performed using Medline and PubMed to provide an overview of the current knowledge on respiratory-virus induced adaptive HI. RESULTS: In HI the immune response towards one antigen results in an alteration of the immune response towards a second antigen. We provide an overview of respiratory virus-induced HI, including viruses such as respiratory syncytial virus (RSV), rhinovirus (RV), coronavirus (CoV) and influenza virus (IV). We discuss T cell receptor (TCR) and humoral cross-reactivity as mechanisms of HI involving those respiratory viruses. Topics covered include HI between respiratory viruses as well as between respiratory viruses and other pathogens. Newly developed vaccines, which have the potential to provide protection against multiple virus strains are also discussed. Furthermore, respiratory viruses have been implicated in the development of autoimmune diseases, such as narcolepsy, Guillain-Barré syndrome, type 1 diabetes or myocarditis. Finally, we discuss the role of respiratory viruses in asthma and the hygiene hypothesis, and review our recent findings on HI between IV and allergens, which leads to protection from experimental asthma. CONCLUSION: Respiratory-virus induced HI may have protective but also detrimental effects on the host. Respiratory viral infections contribute to asthma or autoimmune disease development, but on the other hand, a lack of microbial encounter is associated with an increasing number of allergic as well as autoimmune diseases. Future research might help identify the elements which determine a protective or detrimental outcome in HI-based mechanisms.

Title: Single-dose replicating RNA vaccine induces neutralizing antibodies against SARS-CoV-2 in nonhuman primates Content: The ongoing COVID-19 pandemic, caused by infection with SARS-CoV-2, is having a dramatic and deleterious impact on health services and the global economy. Grim public health statistics highlight the need for vaccines that can rapidly confer protection after a single dose and be manufactured using components suitable for scale-up and efficient distribution. In response, we have rapidly developed repRNA-CoV2S, a stable and highly immunogenic vaccine candidate comprised of an RNA replicon formulated with a novel Lipid InOrganic Nanoparticle (LION) designed to enhance vaccine stability, delivery and immunogenicity. We show that intramuscular injection of LION/repRNA-CoV2S elicits robust anti-SARS-CoV-2 spike protein IgG antibody isotypes indicative of a Type 1 T helper response as well as potent T cell responses in mice. Importantly, a single-dose administration in nonhuman primates elicited antibody responses that potently neutralized SARS-CoV-2. These data support further development of LION/repRNA-CoV2S as a vaccine candidate for prophylactic protection from SARS-CoV-2 infection.

Title: Current Status of the COVID-19 Outbreak and Emerging Management through Pharmaceutical Therapeutic Strategy. Content: The latest SARS COV2 coronavirus contributes to a pandemic of millions of COVID-19. Because there is no defensive immunity in humans and a virus can overcome inborn immune reaction, it can propagate unhindered, mostly in tissues contaminated. No unique therapies for COVID-19 contaminated patients are available at this time. The insights learned from previous respiratory viral infection control have given guidance into COVID-19 therapy. Several complementary treatments have been tentatively introduced in hospital environments such as immune-modulators, antiviral, convalescent plasma transfusions and natural products. In COVID-19 patients, some of these therapies have provided substantial curative benefits. Moreover, numerous studies and clinical trials are being carried out in order to determine the efficacy of current pharmaceutical and natural products and establish possible therapeutic strategies for producing novel COVID-19 medicines. We summarized and defined the modes of mechanism, protection and efficacy on existing therapeutic strategies for diseases linked to COVID-19 infection.

Title: Chapter 36 SARS Content: Abstract Five years after the first severe acute respiratory syndrome (SARS) outbreak, several candidate SARS-coronavirus (CoV) vaccines are at various stages of preclinical and clinical development. Based on the observation that SARSCoV infection is efficiently controlled upon passive transfer of antibodies directed against the spike (S) protein of SARS-CoV, vaccines containing the S protein have been formulated. Animals immunized with inactivated whole virus vaccines or live-recombinant vaccines expressing the SARS-CoV S protein (e.g., using rabies virus, vesicular stomatitis virus, bovine parainfluenza virus type 3, adenovirus, or attenuated vaccinia virus MVA as a vector), as well as mice immunized with DNA vaccines expressing the S protein gene all developed neutralizing antibodies to SARS-CoV and were protected against SARS-CoV challenge. Although much effort has been focused on developing a SARS vaccine, the commercial viability of such a vaccine for SARS-CoV will ultimately depend on whether the virus re-emerges in the near future. This vaccine should induce highly cross-reactive neutralizing antibodies to protect against newly emerging viruses related to SARS-CoV and protect both the gastrointestinal and respiratory tract in the absence of significant side effects. Given the fact that in the previous outbreak mainly the elderly succumbed to the infection, special attention should be given to vaccines that are able to efficiently protect aged individuals.

Title: Multiplex detection and dynamics of IgG antibodies to SARS-CoV2 and the highly pathogenic human coronaviruses SARS-CoV and MERS-CoV Content: BACKGROUND: Knowledge of the COVID-19 epidemic extent and the level of herd immunity is urgently needed to help manage this pandemic. METHODS: We used a panel of 167 samples (77 pre-epidemic and 90 COVID-19 seroconverters) and SARS-CoV1, SARS-CoV2 and MERS-CoV Spike and/or Nucleopcapsid (NC) proteins to develop a high throughput multiplex screening assay to detect IgG antibodies in human plasma. Assay performances were determined by ROC curves analysis. A subset of the COVID-19+ samples (n = 36) were also tested by a commercial NC-based ELISA test and the results compared with those of the novel assay. RESULTS: On samples collected ≥14 days after symptoms onset, the accuracy of the assay is 100 % (95 % CI: 100-100) for the Spike antigen and 99.9 % (95 % CI:99.7-100) for NC. By logistic regression, we estimated that 50 % of the patients have seroconverted at 5.7 ± 1.6; 5.7 ± 1.8 and 7.9 ± 1.0 days after symptoms onset against Spike, NC or both antigens, respectively and all have seroconverted two weeks after symptoms onset. IgG titration in a subset of samples showed that early phase samples present lower IgG titers than those from later phase. IgG to SARS-CoV2 NC cross-reacted at 100 % with SARS-CoV1 NC. Twenty-nine of the 36 (80.5 %) samples tested were positive by the commercial ELISA while 31/36 (86.1 %) were positive by the novel assay. CONCLUSIONS: Our assay is highly sensitive and specific for the detection of IgG antibodies to SARS-CoV2 proteins, suitable for high throughput epidemiological surveys. The novel assay is more sensitive than a commercial ELISA.

Title: Multiplex detection and dynamics of IgG antibodies to SARS-CoV2 and the highly pathogenic human Coronaviruses SARS-CoV and MERS-CoV Content: BACKGROUND: Knowledge of the COVID-19 epidemic extent and the level of herd immunity is urgently needed to help manage this pandemic. METHODS: We used a panel of 167 samples (77 pre-epidemic and 90 COVID-19 seroconverters) and SARS-CoV1, SARS-CoV2 and MERS-CoV Spike and/or Nucleopcapsid (NC) proteins to develop a high throughput multiplex screening assay to detect IgG antibodies in human plasma. Assay performances were determined by ROC curves analysis. A subset of the COVID-19+ samples (n = 36) were also tested by a commercial NC-based ELISA test and the results compared with those of the novel assay. RESULTS: On samples collected ≥14 days after symptoms onset, the accuracy of the assay is 100% (95% CI: 100-100) for the Spike antigen and 99.9% (95% CI:99.7-100) for NC. By logistic regression, we estimated that 50% of the patients have seroconverted at 5.7 ± 1.6; 5.7 ± 1.8 and 7.9 ± 1.0 days after symptoms onset against Spike, NC or both antigens, respectively and all have seroconverted two weeks after symptoms onset. IgG titration in a subset of samples showed that early phase samples present lower IgG titers than those from later phase. IgG to SARS-CoV2 NC cross-reacted at 100% with SARS-CoV1 NC. Twenty-nine of the 36 (80.5%) samples tested were positive by the commercial ELISA while 31/36 (86.1%) were positive by the novel assay. CONCLUSIONS: Our assay is highly sensitive and specific for the detection of IgG antibodies to SARS-CoV2 proteins, suitable for high throughput epidemiological surveys. The novel assay is more sensitive than a commercial ELISA.

Title: In Silico design and characterization of multi-epitopes vaccine for SARS-CoV2 from its spike proteins Content: COVID 19 is disease caused by novel corona virus, SARS-CoV2 originated in China most probably of Bat origin. Till date, no specific vaccine or drug has been discovered to tackle the infections caused by SARS-CoV2. In response to this pandemic, we utilized bioinformatics knowledge to develop efficient vaccine candidate against SARS-CoV2. Designed vaccine was rich in effective BCR and TCR epitopes screened from the sequence of S-protein of SARS-CoV2. Predicted BCR and TCR epitopes were antigenic in nature non-toxic and probably non-allergen. Modelled and refined tertiary structure was predicted as valid for further use. Protein-Protein interaction prediction of TLR2/4 and designed vaccine indicates promising binding. Designed multiepitope vaccine has induced cell mediated and humoral immunity along with increased interferon gamma response. Macrophages and dendritic cells were also found increased over the vaccine exposure. In silico codon optimization and cloning in expression vector indicates that vaccine can be efficiently expressed in E. coli. In conclusion, predicted vaccine is a good antigen, probable no allergen and has potential to induce cellular and humoral immunity.

Title: Fundamental principles of epidemic spread highlight the immediate need for large-scale serological surveys to assess the stage of the SARS-CoV-2 epidemic Content: The spread of a novel pathogenic infectious agent eliciting protective immunity is typically characterised by three distinct phases: (I) an initial phase of slow accumulation of new infections (often undetectable), (II) a second phase of rapid growth in cases of infection, disease and death, and (III) an eventual slow down of transmission due to the depletion of susceptible individuals, typically leading to the termination of the (first) epidemic wave. Before the implementation of control measures (e.g. social distancing, travel bans, etc) and under the assumption that infection elicits protective immunity, epidemiological theory indicates that the ongoing epidemic of SARS-CoV-2 will conform to this pattern. Here, we calibrate a susceptible-infected-recovered (SIR) model to data on cumulative reported SARS-CoV-2 associated deaths from the United Kingdom (UK) and Italy under the assumption that such deaths are well reported events that occur only in a vulnerable fraction of the population. We focus on model solutions which take into consideration previous estimates of critical epidemiological parameters such as the basic reproduction number (R0), probability of death in the vulnerable fraction of the population, infectious period and time from infection to death, with the intention of exploring the sensitivity of the system to the actual fraction of the population vulnerable to severe disease and death. Our simulations are in agreement with other studies that the current epidemic wave in the UK and Italy in the absence of interventions should have an approximate duration of 2-3 months, with numbers of deaths lagging behind in time relative to overall infections. Importantly, the results we present here suggest the ongoing epidemics in the UK and Italy started at least a month before the first reported death and have already led to the accumulation of significant levels of herd immunity in both countries. There is an inverse relationship between the proportion currently immune and the fraction of the population vulnerable to severe disease. This relationship can be used to determine how many people will require hospitalisation (and possibly die) in the coming weeks if we are able to accurately determine current levels of herd immunity. There is thus an urgent need for investment in technologies such as virus (or viral pseudotype) neutralization assays and other robust assays which provide reliable read-outs of protective immunity, and for the provision of open access to valuable data sources such as blood banks and paired samples of acute and convalescent sera from confirmed cases of SARS-CoV-2 to validate these. Urgent development and assessment of such tests should be followed by rapid implementation at scale to provide real-time data. These data will be critical to the proper assessment of the effects of social distancing and other measures currently being adopted to slow down the case incidence and for informing future policy direction.

Title: The modelling of COVID19 pathways sheds light on mechanisms, opportunities and on controversial interpretations of medical treatments. v2 Content: The new coronavirus (2019-nCoV or SARS-CoV2), inducing the current pandemic disease (COVID-19) and causing pneumoniae in humans, is dramatically increasing in epidemic scale since its first appearance in Wuhan, China, in December 2019. The first infection from epidemic coronaviruses in 2003 fostered the spread of an overwhelming amount of related scientific efforts. The manifold aspects that have been raised, as well as their redundancy offer precious information that has been underexploited and needs to be critically re-evaluated, appropriately used and offered to the whole community, from scientists, to medical doctors, stakeholders and common people. These efforts will favour a holistic view on the comprehension, prevention and development of strategies (pharmacological, clinical etc) as well as common intervention against the new coronavirus spreading. Here we describe a model that emerged from our analysis that was focused on the Renin Angiotensin System (RAS) and the possible routes linking it to the viral infection. because the infection is mediated by the viral receptor on human cell membranes Angiotensin Converting Enzyme (ACE2), which is a key component in RAS signalling. The model depicts the main pathways determining the disease and the molecular framework for its establishment, and can help to shed light on mechanisms involved in the infection. It promptly gives an answer to some of the controversial, and still open, issues concerning predisposing conditions and medical treatments that protect from or favour the severity of the disease (such as the use of ACE inhibitors or ARBs/sartans), or to the sex related biases in the affected population. The model highlights novel opportunities for further investigations, diagnosis and appropriate intervention to understand and fight COVID19.

Title: Control of influenza virus infection by immunity to conserved viral features. Content: Influenza has circulated among humans for centuries and kills more people than many newly emerging diseases. The present methods for control of influenza are not adequate, especially for dealing with a pandemic. In the face of a rapidly spreading outbreak, a race to isolate the virus and prepare a vaccine would probably not succeed in time to avoid great losses. Thus, additional anti-infection strategies are needed. Broad cross-protection against widely divergent influenza A subtypes is readily achieved in animals by several means of immunization. How does cross-protection work in animals, and can we apply what we have learned about it to induce broad cross-protection in humans?

Title: A single-dose live-attenuated YF17D-vectored SARS-CoV2 vaccine candidate Content: The explosively expanding COVID-19 pandemic urges the development of safe, efficacious and fast-acting vaccines to quench the unrestrained spread of SARS-CoV-2. Several promising vaccine platforms, developed in recent years, are leveraged for a rapid emergency response to COVID-191. We employed the live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express the prefusion form of the SARS-CoV-2 Spike antigen. In mice, the vaccine candidate, tentatively named YF-S0, induces high levels of SARS-CoV-2 neutralizing antibodies and a favorable Th1 cell-mediated immune response. In a stringent hamster SARS-CoV-2 challenge model2, vaccine candidate YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose confers protection from lung disease in most vaccinated animals even within 10 days. These results warrant further development of YF-S0 as a potent SARS-CoV-2 vaccine candidate.

Title: Serological differentiation between COVID-19 and SARS infections Content: In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by SARS-CoV-2, multiple diagnostic tests are required for acute disease diagnosis, contact tracing, monitoring asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed. Unlike PCR tests which are highly specific, cross-reactivity is a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. SARS-CoV is genetically related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus in the genus Betacoronavirus of family Coronaviridae. We developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. There is significant cross-reactivity when N protein of either virus is used. The S1 or RBD regions from the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. We found that SARS survivors all have significant levels of antibodies remaining in their blood 17 years after infection. Anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

Title: T cells found in COVID-19 patients ‘bode well’ for long-term immunity Content: SARS-CoV-2, the virus that causes COVID-19, has been unclear Now, two studies reveal that infected people harbor T cells that target the virus—and may help them recover Both studies also found that some people never infected with SARS-CoV-2 have these cellular defenses, most likely because they were previously infected with other coronaviruses “This is encouraging data,” says virologist Angela Rasmussen of Columbia University Although the studies don’t clarify whether people who clear a SARS-CoV-2 infection can ward off the virus in the future, both identified strong T cell responses to it, which “bodes well for the development of long-term protective immunity,” Rasmussen says The findings could also help researchers create better vaccines

Title: Ribosomal proteins as a possible tool for blocking SARS-COV 2 virus replication for a potential prospective treatment Content: Coronavirus disease (COVID-19) is caused by SARS-COV2 and has resulted in more than four million cases globally and the death cases exceeded 300,000. Normally, a range of surviving and propagating host factors must be employed for the completion of the infectious process including RPs. Viral protein biosynthesis involves the interaction of numerous RPs with viral mRNA, proteins which are necessary for viruses replication regulation and infection inside the host cells. Most of these interactions are crucial for virus activation and accumulation. However, only small percentage of these proteins is specifically responsible for host cells protection by triggering the immune pathway against virus. This research proposes RPs extracted from bacillus sp. and yeast as new forum for the advancement of antiviral therapy. Hitherto, antiviral therapy with RPs-involving viral infection has not been widely investigated as critical targets. Also, exploring antiviral strategy based on RPs could be a promising guide for more potential therapeutics.

Title: Ribosomal proteins as a possible tool for blocking SARS-COV 2 virus replication for a potential prospective treatment. Content: Coronavirus disease (COVID-19) is caused by SARS-COV2 and has resulted in more than four million cases globally and the death cases exceeded 300,000. Normally, a range of surviving and propagating host factors must be employed for the completion of the infectious process including RPs. Viral protein biosynthesis involves the interaction of numerous RPs with viral mRNA, proteins which are necessary for viruses replication regulation and infection inside the host cells. Most of these interactions are crucial for virus activation and accumulation. However, only small percentage of these proteins is specifically responsible for host cells protection by triggering the immune pathway against virus. This research proposes RPs extracted from bacillus sp. and yeast as new forum for the advancement of antiviral therapy. Hitherto, antiviral therapy with RPs-involving viral infection has not been widely investigated as critical targets. Also, exploring antiviral strategy based on RPs could be a promising guide for more potential therapeutics.

Title: Cross-immunity between respiratory coronaviruses may limit COVID-19 fatalities Content: Of the seven coronaviruses associated with disease in humans, SARS-CoV, MERS-CoV and SARS-CoV-2 cause considerable mortality but also share significant sequence homology, and potentially antigenic epitopes capable of inducing an immune response. The degree of similarity is such that perhaps prior exposure to one virus could confer partial immunity to another. Indeed, data suggests a considerable amount of cross-reactivity and recognition by the hosts immune response between different coronavirus infections. While the ongoing COVID-19 outbreak rapidly overwhelmed medical facilities of particularly Europe and North America, accounting for 78% of global deaths, only 8% of deaths have occurred in Asia where the outbreak originated. Interestingly, Asia and the Middle East have previously experienced multiple rounds of coronavirus infections, perhaps suggesting buildup of acquired immunity to the causative SARS-CoV-2 that underlies COVID-19. This article hypothesizes that a causative factor underlying such low morbidity in these regions is perhaps (at least in part) due to acquired immunity from multiple rounds of coronavirus infections and discusses the mechanisms and recent evidence to support such assertions. Further investigations of such phenomenon would allow us to examine strategies to confer protective immunity, perhaps aiding vaccine development.

Title: Serologic cross-reactivity of SARS-CoV-2 with endemic and seasonal Betacoronaviruses Content: In order to properly understand the spread of SARS-CoV-2 infection and development of humoral immunity, researchers have evaluated the presence of serum antibodies of people worldwide experiencing the pandemic. These studies rely on the use of recombinant proteins from the viral genome in order to identify serum antibodies that recognize SARS-CoV-2 epitopes. Here, we discuss the cross-reactivity potential of SARS-CoV-2 antibodies with the full spike proteins of four other Betacoronaviruses that cause disease in humans, MERS-CoV, SARS-CoV, HCoV-OC43, and HCoV-HKU1. Using enzyme-linked immunosorbent assays (ELISAs), we detected the potential cross-reactivity of antibodies against SARS-CoV-2 towards the four other coronaviruses, with the strongest cross-recognition between SARS-CoV-2 and SARS /MERS-CoV antibodies, as expected based on sequence homology of their respective spike proteins. Further analysis of cross-reactivity could provide informative data that could lead to intelligently designed pan-coronavirus therapeutics or vaccines.

Title: Conserved epitopes of influenza A virus inducing protective immunity and their prospects for universal vaccine development Content: Influenza A viruses belong to the best studied viruses, however no effective prevention against influenza infection has been developed. The emerging of still new escape variants of influenza A viruses causing epidemics and periodic worldwide pandemics represents a threat for human population. Therefore, current, hot task of influenza virus research is to look for a way how to get us closer to a universal vaccine. Combination of chosen conserved antigens inducing cross-protective antibody response with epitopes activating also cross-protective cytotoxic T-cells would offer an attractive strategy for improving protection against drift variants of seasonal influenza viruses and reduces the impact of future pandemic strains. Antigenically conserved fusion-active subunit of hemagglutinin (HA2 gp) and ectodomain of matrix protein 2 (eM2) are promising candidates for preparation of broadly protective HA2- or eM2-based vaccine that may aid in pandemic preparedness. Overall protective effect could be achieved by contribution of epitopes recognized by cytotoxic T-lymphocytes (CTL) that have been studied extensively to reach much broader control of influenza infection. In this review we present the state-of-art in this field. We describe known adaptive immune mechanisms mediated by influenza specific B- and T-cells involved in the anti-influenza immune defense together with the contribution of innate immunity. We discuss the mechanisms of neutralization of influenza infection mediated by antibodies, the role of CTL in viral elimination and new approaches to develop epitope based vaccine inducing cross-protective influenza virus-specific immune response.

Title: Elevated expression of ACE2 in tumor-adjacent normal tissues of cancer patients Content: The rapidly developing COVID-19 pandemic has raised a concern that cancer patients may have increased susceptibility to SARS-CoV-2 infection. This discussion has mostly focused on therapy-induced immune suppression. Here, we examined the expression patterns of ACE2, the receptor through which SARX-CoV2 enters human cells, and found that ACE2 mRNA levels are elevated in tumor-adjacent normal tissues of cancer patients, including in normal-adjacent lung tissues of lung cancer patients. These observations raise the possibility that the elevated COVID-19 risk of cancer patients may not be limited to those undergoing immune-suppressing treatment.

Title: Clinical performance of SARS-CoV-2 IgG antibody tests and potential protective immunity Content: As the current SARS-CoV-2 pandemic continues, serological assays are urgently needed for rapid diagnosis, contact tracing and for epidemiological studies. So far, there is little data on how commercially available tests perform with real patient samples and if detected IgG antibodies provide protective immunity. Focusing on IgG antibodies, we demonstrate the performance of two ELISA assays (Euroimmun SARS-CoV-2 IgG & Vircell COVID-19 ELISA IgG) in comparison to one lateral flow assay ((LFA) FaStep COVID-19 IgG/IgM Rapid Test Device) and two in-house developed assays (immunofluorescence assay (IFA) and plaque reduction neutralization test (PRNT)). We tested follow up serum/plasma samples of individuals PCR-diagnosed with COVID-19. Most of the SARS-CoV-2 samples were from individuals with moderate to severe clinical course, who required an in-patient hospital stay. For all examined assays, the sensitivity ranged from 58.8 to 76.5% for the early phase of infection (days 5-9) and from 93.8 to 100% for the later period (days 10-18) after PCR-diagnosed with COVID-19. With exception of one sample, all positive tested samples in the analysed cohort, using the commercially available assays examined (including the in-house developed IFA), demonstrated neutralizing (protective) properties in the PRNT, indicating a potential protective immunity to SARS-CoV-2. Regarding specificity, there was evidence that samples of endemic coronavirus (HCoV-OC43, HCoV-229E) and Epstein Barr virus (EBV) infected individuals cross-reacted in the ELISA assays and IFA, in one case generating a false positive result (may giving a false sense of security). This need to be further investigated.

Title: Serological differentiation between COVID-19 and SARS infections. Content: In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by the SARS-CoV-2 virus, multiple diagnostic tests are required globally for acute disease diagnosis, contact tracing, monitoring of asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed to fulfil the other requirements. Unlike PCR tests which are highly specific for each virus, cross-reactivity could potentially be a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. Among the human pathogens, SARS-CoV is genetically most related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus (SARSr-CoV) in the genus Betacoronavirus of family Coronaviridae. In this study, we developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. Our results indicate that there is a significant cross-reactivity when N protein of either SARS-CoV or SARS-CoV-2 is used. The S1 or RBD derived the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. Finally, we found that SARS survivors all have significant level of antibodies remaining in their blood 17 years after infection. We discovered that anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

Title: Serological differentiation between COVID-19 and SARS infections Content: In response to the coronavirus disease 2019 (COVID-19) outbreak, caused by the SARS-CoV-2 virus, multiple diagnostic tests are required globally for acute disease diagnosis, contact tracing, monitoring of asymptomatic infection rates and assessing herd immunity. While PCR remains the frontline test of choice in the acute diagnostic setting, serological tests are urgently needed to fulfil the other requirements. Unlike PCR tests which are highly specific for each virus, cross-reactivity could potentially be a major challenge for COVID-19 antibody tests considering there are six other coronaviruses known to infect humans. Among the human pathogens, SARS-CoV is genetically most related to SARS-CoV-2 sharing approximately 80% sequence identity and both belong to the species SARS related coronavirus (SARSr-CoV) in the genus Betacoronavirus of family Coronaviridae. In this study, we developed and compared the performance of four different serological tests to comprehensively assess the cross-reactivity between COVID-19 and SARS patient sera. Our results indicate that there is a significant cross-reactivity when N protein of either SARS-CoV or SARS-CoV-2 is used. The S1 or RBD derived the spike (S) protein offers better specificity. Amongst the different platforms, capture ELISA performed best. Finally, we found that SARS survivors all have significant level of antibodies remaining in their blood 17 years after infection. We discovered that anti-N antibodies waned more than anti-RBD antibodies, and the latter is known to play a more important role in providing protective immunity.

Title: Vaccination of mice with recombinant baculovirus expressing spike or nucleocapsid protein of SARS-like coronavirus generates humoral and cellular immune responses Content: Abstract Continuous efforts have been made to develop a prophylactic vaccine against severe acute respiratory syndrome coronavirus (SARS-CoV). In this study, two recombinant baculoviruses, vAc-N and vAc-S, were constructed, which contained the mammalian-cell activate promoter element, human elongation factor 1α-subunit (EF-1α), the human cytomegalovirus (CMV) immediate-early promoter, and the nucleocapsid (N) or spike (S) gene of bat SARS-like CoV (SL-CoV) under the control of the CMV promoter. Mice were subcutaneously and intraperitoneally injected with recombinant baculovirus, and both humoral and cellular immune responses were induced in the vaccinated groups. The secretion level of IFN-γ was much higher than that of IL-4 in vAc-N or vAc-S immunized groups, suggesting a strong Th1 bias towards cellular immune responses. Additionally, a marked increase of CD4 T cell immune responses and high levels of anti-SARS-CoV humoral responses were also detected in the vAc-N or vAc-S immunized groups. In contrast, there were significantly weaker cellular immune responses, as well as less antibody production than in the control groups. Our data demonstrates that the recombinant baculovirus can serve as an effective vaccine strategy. In addition, because effective SARS vaccines should act to not only prevent the reemergence of SARS-CoV, but also to provide cross-protection against SL-CoV, findings in this study may have implications for developing such cross-protective vaccines.

Title: Vaccines Content: Vaccines are predominantly used for prevention; that means they should establish a protection in immunized people or animals which will protect them from a possible infection and the subsequent illness when they come into contact with the respective pathogens. Fundamentally, there are two kinds of immunization: active and passive. The latter is based on the administration of immunoglobulin preparations that can neutralize a specific virus. Therefore, passive vaccination is applied only in special cases, such as when the person to be protected recently had verifiable contact with a specific virus (postexposure prophylaxis), or if the risk of exposure to pathogens cannot be ruled out in the following weeks and an active vaccination is not possible, as in short-term planned trips to Third World countries (exposure prophylaxis). An example is the administration of antibodies specific for hepatitis B virus in cases of contamination with blood from people who have an acute or chronically persistent infection with this virus, and thus have high concentrations of infectious particles in the blood. Such accidents occur primarily in medical personnel by needlestick injury (10.1007/978-3-642-20718-1_19). In certain cases, the administration is performed in combination with an active vaccination (active–passive immunization). Specific immunoglobulin preparations are also administered when people have been bitten by animals that may be infected with the rabies virus (10.1007/978-3-642-20718-1_15). In the case of early application (together with an active vaccination), the antibodies can neutralize the virus, and impede its spread in the body. Since the time between contact with the virus and its spread in the organism is often very short, passive immunization is limited to a period shortly before or after exposure to the infective agent (usually within 4 days). Therefore, it is reserved for cases in which the contact with the potential pathogen is well documented and the type of infection is known, and when an appropriate immunoglobulin preparation is available. The protection afforded by antibody preparations lasts just a few weeks, as immunoglobulins are rapidly degraded in the organism. Therefore, postexposure administration of active vaccines is increasingly preferred, e.g. in the context of outbreak-control vaccination. In veterinary medicine, passive immunization is employed occasionally in young animals which were born in a flock with high infection pressure. This approach is applied, for example, in kennels when infections occur with canine parvovirus (10.1007/978-3-642-20718-1_20). However, its value is controversial, as the immunoglobulins administered hinder the more advantageous active immunization.

Title: A systematic review of antibody mediated immunity to coronaviruses: antibody kinetics, correlates of protection, and association of antibody responses with severity of disease Content: The duration and nature of immunity generated in response to SARS-CoV-2 infection is unknown. Many public health responses and modeled scenarios for COVID-19 outbreaks caused by SARSCoV-2 assume that infection results in an immune response that protects individuals from future infections or illness for some amount of time. The timescale of protection is a critical determinant of the future impact of the pathogen. The presence or absence of protective immunity due to infection or vaccination (when available) will affect future transmission and illness severity. The dynamics of immunity and nature of protection are relevant to discussions surrounding therapeutic use of convalescent sera as well as efforts to identify individuals with protective immunity. Here, we review the scientific literature on antibody immunity to coronaviruses, including SARS-CoV-2 as well as the related SARS-CoV-1, MERS-CoV and human endemic coronaviruses (HCoVs). We reviewed 1281 abstracts and identified 322 manuscripts relevant to 5 areas of focus: 1) antibody kinetics, 2) correlates of protection, 3) immunopathogenesis, 4) antigenic diversity and cross-reactivity, and 5) population seroprevalence. While studies of SARS-CoV-2 are necessary to determine immune responses to it, evidence from other coronaviruses can provide clues and guide future research.

Title: SARS-CoV-2 Antibody Testing – Questions to be asked Content: ABSTRACT SARS-CoV-2 infection and development of COVID-19 disease presents a major healthcare challenge of global dimensions. Laboratory diagnostics of infected patients, and the assessment of immunity against the SARS-CoV-2 virus presents a major cornerstone in handling the pandemic. Currently there is an increase in demand of antibody testing and a large number of tests are already marketed or in the late stage of development. However, the interpretation of test results depends on many variables and factors, including sensitivity, specificity, potential cross-reactivity and cross-protectivity; the diagnostic value of antibodies of different isotypes, the use of antibody testing in identification of acutely ill patients or in epidemiological settings. In this article the recently established COVID-19 Task Force of the German Society for Clinical Chemistry and Laboratory Medicine (DGKL) addresses these issues based on the currently available datasets in this rapidly moving field.

Title: Systemic Immunobiological, Immunosuppressant and Oncologic Agents for the Treatment of Dermatologic Diseases during the SARS‐Cov‐2 (COVID19) Pandemic Emergency: a Quick Review for a Quick Consultation Content: The Precision Medicine Era has helped to better manage patients with immunological and oncological disease, improving the quality of life of this class of patients. Regarding the management of these patients and positivity to SARS‐Cov2, currently, limited data is available and information is evolving. In this quick review we have analyzed the mechanisms of action and related infective risk of drugs used for the treatment of immune‐mediated and oncologic skin conditions during the daily clinical practice. In general immunosuppressant and antineoplastic agents for dermatologic treatments do not require suspension and do not require special measures, if not those commonly observed. In the case of a COVID19 patient with complication (such as pneumonia, respiratory failure), treatment suspension should always be considered after taking into account the general condition of the patient, the risk‐benefit ratio and the pathophysiology of COVID19 infection. The COVID19 emergency pandemic does not imply an under‐treatment of existing skin conditions, which together with the SARS‐Cov2 infection may jeopardize the patient's life. This article is protected by copyright. All rights reserved.

Title: Protective immunity after COVID-19 has been questioned: What can we do without SARS-CoV-2-IgG detection? Content: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a severe acute respiratory syndrome that is called COVID-19. Clinical manifestations of COVID-19 include diarrhea, pneumonia, lymphopenia, exhausted lymphocytes, and pro-inflammatory cytokine production. Immunology is part of the process of clinical evolution, but there are some questions around immunity-based protection: (1) why some infected people have only mild symptoms of the disease or are asymptomatic; (2) why delayed and weak antibody responses are associated with severe outcomes; and (3) why positivity in molecular tests does not represent protective antibody IgG. Perhaps T cell responses may be the key to solving those questions. SARS-CoV-2-specific memory T cells persist in peripheral blood and may be capable of providing effective information about protective immunity. The T cells studies can be helpful in elucidating the pathways for development of vaccines, therapies, and diagnostics for COVID-19 and for filling these immunology knowledge gaps.

Title: Protective immunity after COVID-19 has been questioned: what can we do without SARS-CoV-2-IgG detection? Content: Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a severe acute respiratory syndrome that is called COVID-19. Clinical manifestations of COVID-19 include diarrhea, pneumonia, lymphopenia, exhausted lymphocytes, and pro-inflammatory cytokine production. Immunology is part of the process of clinical evolution, but there are some questions around immunity-based protection: (1) why some infected people have only mild symptoms of the disease or are asymptomatic; (2) why delayed and weak antibody responses are associated with severe outcomes; and (3) why positivity in molecular tests does not represent protective antibody IgG. Perhaps T cell responses may be the key to solving those questions. SARS-CoV-2-specific memory T cells persist in peripheral blood and may be capable of providing effective information about protective immunity. The T cells studies can be helpful in elucidating the pathways for development of vaccines, therapies, and diagnostics for COVID-19 and for filling these immunology knowledge gaps.

Title: Controlled, double-blind, randomized trial to assess the efficacy and safety of hydroxychloroquine chemoprophylaxis in SARS CoV2 infection in healthcare personnel in the hospital setting: A structured summary of a study protocol for a randomised controlled trial Content: BACKGROUND: SARS-CoV-2 infection presents a high transmission in the group of health professionals in Spain (12-15% infected). Currently there is no accepted chemoprophylaxis but hydroxychloroquine (HDQ) is known to inhibit the coronavirus in vitro. Our hypothesis is that oral administration of hydroxychloroquine to healthcare professionals can reduce the incidence and prevalence of infection as well as its severity in this group. METHODS: Design: Prospective, single center, double blind, randomised, controlled trial (RCT). Participants: Adult health-care professionals (18-65 years) working in areas of high exposure and high risk of transmission of SARS-COV-2 (COVID areas, Intensive Care Unit –ICUs-, Emergency, Anesthesia and all those performing aerosol-generating procedures) will be included. Exclusion criteria include previous infection with SARS CoV2 (positive SARS-CoV-2 PCR or IgG serology), pregnancy or lactation, any contraindication to hydroxychloroquine or evidence of unstable or clinically significant systemic disease. INTERVENTIONS: Patients will be randomized (1:1) to receive once-daily oral Hydroxychloroquine 200mg for two months (HC group) or placebo (P group) in addition to the protective measures appropriate to the level of exposure established by the hospital. A serological evaluation will be carried out every 15 days with PCR in case of seroconversion, symptoms or risk exposure. Primary outcome is the percentage of subjects presenting infection (seroconversion and/or PCR +ve) by the SARS-Cov-2 virus during the observation period. Additionally, both the percentage of subjects in each group presenting Pneumonia with severity criteria (Curb 65 ≥2) and that of subjects requiring admission to ICU will be determined. DISCUSSION: While awaiting a vaccine, hygiene measures, social distancing and personal protective equipment are the only primary prophylaxis measures against SARS-CoV-2, but they have not been sufficient to protect our healthcare professionals. Some evidence of the in vitro efficacy of hydroxychloroquine against this virus is known, along with some clinical data that would support the study of this drug in the chemoprophylaxis of infection. However, there are still no data from controlled clinical trials in this regard. If our hypothesis is confirmed, hydroxychloroquine can help professionals fight this infection with more guarantees. PARTICIPANTS: This is a single-center study that will be carried out at the Marqués de Valdecilla University Hospital. 450 health professionals working at the Hospital Universitario Marqués de Valdecilla in areas of high exposure and high risk of transmission of SARS COV2 (COVID hospital areas, Intensive Care Unit, Emergency, Anesthesia and all those performing aerosol-generating procedures) will be included. Inclusion criteria: 1) Health professionals aged between 18 and 65 years (inclusive) at the time of the first screening visit; 2) They must provide signed written informed consent and agree to comply with the study protocol; 3) Active work in high exposure areas during the last two weeks and during the following weeks. Exclusion criteria: 1) Previous infection with SARS CoV2 (positive coronavirus PCR or positive serology with SARS Cov2 negative PCR and absence of symptoms); 2) Current treatment with hydroxychloroquine or chloroquine; 3) Hypersensitivity, allergy or any contraindication for taking hydroxychloroquine, in the technical sheet; 4) Previous or current treatment with tamoxifen or raloxifene; 5) Previous eye disease, especially maculopathy; 6) Known heart failure (Grade III to IV of the New York Heart Association classification) or prolonged QTc; 7) Any type of cancer (except basal cell) in the last 5 years; 6) Refusal to give informed consent; 8) Evidence of any other unstable or clinically significant untreated immune, endocrine, hematological, gastrointestinal, neurological, neoplastic or psychiatric illness; 9) Antibodies positive for the human immunodeficiency virus; 10) Significant kidney or liver disease; 11) Pregnancy or lactation. INTERVENTION AND COMPARATOR: 1. Intervention: (n = 225): One 200 mg hydroxychloroquine sulfate coated tablet once daily for two months. 2. Comparator (control group) (n = 225): One hydroxychloroquine placebo tablet (identical to that of the drug) once daily for two months. MAIN OUTCOMES: number and percentage of healthcare personnel presenting symptomatic and asymptomatic infection (see “Diagnosis of SARS CoV2 infection” below) by the SARS-Cov2 virus during the study observation period (8 weeks) in both treatment arms; number and percentage of healthcare personnel in each group presenting with Pneumonia with severity criteria (Curb 65 ≥2) and number and percentage of healthcare personnel requiring admission to the Intensive Care Unit (ICU) in both treatment arms. DIAGNOSIS OF SARS COV2 INFECTION: Determination of IgA, IgM and IgG type antibodies against SARS-CoV-2 using the Anti-SARS-CoV-2 ELISA kit (EUROIMMUN Medizinische Labordiagnostika AG, Germany) every two weeks. In cases of seroconversion, a SARS-CoV-2 PCR will be performed to rule out / confirm an active infection (RT-PCR in One Step: RT performed with mastermix (Takara) and IDT probes, following protocol published and validated by the CDC Evaluation of COVID-19 in case of SARS-CoV-2 infection RANDOMISATION: Participants will be allocated to intervention and comparator groups according to a balanced randomization scheme (1: 1). The assignment will be made through a computer-generated numeric sequence for all participants BLINDING (MASKING): Both participants and investigators responsible for recruiting and monitoring participants will be blind to the assigned arm. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): Taking into account the current high prevalence of infection in healthcare personnel in Spain (up to 15%), to detect a difference equal to or greater than 8% in the percentage estimates through a two-tailed 95% CI, with a statistical power of 80% and a dropout rate of 5%, a total of 450 participants will need to be included (250 in each arm). TRIAL STATUS: The protocol approved by the health authorities in Spain (Spanish Agency for Medicines and Health Products “AEMPS”) and the Ethics and Research Committee of Cantabria (CEIm Cantabria) corresponds to version 1.1 of April 2, 2020. Currently, recruitment has not yet started, with the start scheduled for the second week of May 2020. TRIAL REGISTRATION: Eudra CT number: 2020-001704-42 (Registered on 29 March 2020) FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).

Title: Controlled, double-blind, randomized trial to assess the efficacy and safety of hydroxychloroquine chemoprophylaxis in SARS CoV2 infection in healthcare personnel in the hospital setting: A structured summary of a study protocol for a randomised controlled trial Content: BACKGROUND: SARS-CoV-2 infection presents a high transmission in the group of health professionals in Spain (12-15% infected). Currently there is no accepted chemoprophylaxis but hydroxychloroquine (HDQ) is known to inhibit the coronavirus in vitro. Our hypothesis is that oral administration of hydroxychloroquine to healthcare professionals can reduce the incidence and prevalence of infection as well as its severity in this group. METHODS: Design: Prospective, single center, double blind, randomised, controlled trial (RCT). PARTICIPANTS: Adult health-care professionals (18-65 years) working in areas of high exposure and high risk of transmission of SARS-COV-2 (COVID areas, Intensive Care Unit -ICUs-, Emergency, Anesthesia and all those performing aerosol-generating procedures) will be included. Exclusion criteria include previous infection with SARS CoV2 (positive SARS-CoV-2 PCR or IgG serology), pregnancy or lactation, any contraindication to hydroxychloroquine or evidence of unstable or clinically significant systemic disease. INTERVENTIONS: Patients will be randomized (1:1) to receive once-daily oral Hydroxychloroquine 200mg for two months (HC group) or placebo (P group) in addition to the protective measures appropriate to the level of exposure established by the hospital. A serological evaluation will be carried out every 15 days with PCR in case of seroconversion, symptoms or risk exposure. Primary outcome is the percentage of subjects presenting infection (seroconversion and/or PCR +ve) by the SARS-Cov-2 virus during the observation period. Additionally, both the percentage of subjects in each group presenting Pneumonia with severity criteria (Curb 65 ≥2) and that of subjects requiring admission to ICU will be determined. DISCUSSION: While awaiting a vaccine, hygiene measures, social distancing and personal protective equipment are the only primary prophylaxis measures against SARS-CoV-2, but they have not been sufficient to protect our healthcare professionals. Some evidence of the in vitro efficacy of hydroxychloroquine against this virus is known, along with some clinical data that would support the study of this drug in the chemoprophylaxis of infection. However, there are still no data from controlled clinical trials in this regard. If our hypothesis is confirmed, hydroxychloroquine can help professionals fight this infection with more guarantees. PARTICIPANTS: This is a single-center study that will be carried out at the Marqués de Valdecilla University Hospital. 450 health professionals working at the Hospital Universitario Marqués de Valdecilla in areas of high exposure and high risk of transmission of SARS COV2 (COVID hospital areas, Intensive Care Unit, Emergency, Anesthesia and all those performing aerosol-generating procedures) will be included. INCLUSION CRITERIA: 1) Health professionals aged between 18 and 65 years (inclusive) at the time of the first screening visit; 2) They must provide signed written informed consent and agree to comply with the study protocol; 3) Active work in high exposure areas during the last two weeks and during the following weeks. EXCLUSION CRITERIA: 1) Previous infection with SARS CoV2 (positive coronavirus PCR or positive serology with SARS Cov2 negative PCR and absence of symptoms); 2) Current treatment with hydroxychloroquine or chloroquine; 3) Hypersensitivity, allergy or any contraindication for taking hydroxychloroquine, in the technical sheet; 4) Previous or current treatment with tamoxifen or raloxifene; 5) Previous eye disease, especially maculopathy; 6) Known heart failure (Grade III to IV of the New York Heart Association classification) or prolonged QTc; 7) Any type of cancer (except basal cell) in the last 5 years; 6) Refusal to give informed consent; 8) Evidence of any other unstable or clinically significant untreated immune, endocrine, hematological, gastrointestinal, neurological, neoplastic or psychiatric illness; 9) Antibodies positive for the human immunodeficiency virus; 10) Significant kidney or liver disease; 11) Pregnancy or lactation. INTERVENTION AND COMPARATOR: Two groups will be analyzed with a 1: 1 randomization rate. 1)Intervention: (n = 225): One 200 mg hydroxychloroquine sulfate coated tablet once daily for two months.2)Comparator (control group) (n = 225): One hydroxychloroquine placebo tablet (identical to that of the drug) once daily for two months MAIN OUTCOMES: The primary outcome of this study will be to evaluate: number and percentage of healthcare personnel presenting symptomatic and asymptomatic infection (see "Diagnosis of SARS CoV2 infection" below) by the SARS-Cov2 virus during the study observation period (8 weeks) in both treatment arms;number and percentage of healthcare personnel in each group presenting with Pneumonia with severity criteria (Curb 65 ≥2) and number and percentage of healthcare personnel requiring admission to the Intensive Care Unit (ICU) in both treatment arms. DIAGNOSIS OF SARS COV2 INFECTION: Determination of IgA, IgM and IgG type antibodies against SARS-CoV-2 using the Anti-SARS-CoV-2 ELISA kit (EUROIMMUN Medizinische Labordiagnostika AG, Germany) every two weeks. In cases of seroconversion, a SARS-CoV-2 PCR will be performed to rule out / confirm an active infection (RT-PCR in One Step: RT performed with mastermix (Takara) and IDT probes, following protocol published and validated by the CDC Evaluation of COVID-19 in case of SARS-CoV-2 infection RANDOMISATION: Participants will be allocated to intervention and comparator groups according to a balanced randomization scheme (1: 1). The assignment will be made through a computer-generated numeric sequence for all participants BLINDING (MASKING): Both participants and investigators responsible for recruiting and monitoring participants will be blind to the assigned arm. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): Taking into account the current high prevalence of infection in healthcare personnel in Spain (up to 15%), to detect a difference equal to or greater than 8% in the percentage estimates through a two-tailed 95% CI, with a statistical power of 80% and a dropout rate of 5%, a total of 450 participants will need to be included (250 in each arm). TRIAL STATUS: The protocol approved by the health authorities in Spain (Spanish Agency for Medicines and Health Products "AEMPS") and the Ethics and Research Committee of Cantabria (CEIm Cantabria) corresponds to version 1.1 of April 2, 2020. Currently, recruitment has not yet started, with the start scheduled for the second week of May 2020. TRIAL REGISTRATION: Eudra CT number: 2020-001704-42 (Registered on 29 March 2020) FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).

Title: Possible therapeutic role of a highly standardized mixture of active compounds derived from cultured Lentinula edodes mycelia (AHCC) in patients infected with 2019 novel coronavirus Content: The outbreak of SARS-CoV-2 disease (COVID-19) is currently, March 2020, affecting more than 100,000 people worldwide and, according to the WHO (World Health Organization), a pandemic is shortly expected. The virus infects the lower respiratory tract and causes severe pneumonia and mortality in approximately 10% and 3-5%, respectively, of cases, mainly among the elderly and/or people affected by other diseases. AHCC is an α-glucan-based standardized mushroom extract that has been extensively investigated as an immunostimulant both in animals and/or in humans affected by West Nile virus, influenza virus, avian influenza virus, hepatitis C virus, papillomavirus, herpes virus, hepatitis B virus and HIV by promoting a regulated and protective immune response. Although the efficacy of AHCC has not yet been specifically evaluated with respect to SARS-CoV-2 disease, its action in promoting a protective response to a wide range of viral infections, and the current absence of effective vaccines, could support its use in the prevention of diseases provoked by human pathogenic coronavirus, including COVID-19.

Title: Possible therapeutic role of a highly standardized mixture of active compounds derived from cultured Lentinula edodes mycelia (AHCC) in patients infected with 2019 novel coronavirus. Content: The outbreak of SARS-CoV-2 disease (COVID-19) is currently, March 2020, affecting more than 100000 people worldwide and, according to the WHO (World Health Organization), a pandemic is shortly expected. The virus infects the lower respiratory tract and causes severe pneumonia and mortality in approximately 10% and 3-5%, respectively, of cases, mainly among the elderly and/or people affected by other diseases. AHCC is an α-glucan-based standardized mushroom extract that has been extensively investigated as an immunostimulant both in animals and/or in humans affected by West Nile virus, influenza virus, avian influenza virus, hepatitis C virus, papillomavirus, herpes virus, hepatitis B virus and HIV by promoting a regulated and protective immune response. Although the efficacy of AHCC has not yet been specifically evaluated with respect to SARS-CoV-2 disease, its action in promoting a protective response to a wide range of viral infections, and the current absence of effective vaccines, could support its use in the prevention of diseases provoked by human pathogenic coronavirus, including COVID-19.

Title: Airway Memory CD4(+) T Cells Mediate Protective Immunity against Emerging Respiratory Coronaviruses Content: Two zoonotic coronaviruses (CoV), SARS-CoV and MERS-CoV have crossed species to cause severe human respiratory disease. Here, we showed that induction of airway memory CD4(+) T cells specific for a conserved epitope shared by SARS-CoV and MERS-CoV is a potential strategy for developing pan-coronavirus vaccines. Airway memory CD4(+) T cells differed phenotypically and functionally from lung-derived cells and were crucial for protection against both CoVs in mice. Protection was interferon-γ-dependent and required early induction of robust innate and virus-specific CD8(+) T cell responses. The conserved epitope was also recognized in SARS-CoV and MERS-CoV-infected human leukocyte antigen DR2 and DR3 transgenic mice, indicating potential relevance in human populations. Additionally, this epitope was cross-protective between human and bat CoVs, the progenitors for many human CoVs. Vaccine strategies that induce airway memory CD4(+) T cells targeting conserved epitopes may have broad applicability in the context of new CoV and other respiratory virus outbreaks.

Title: Lack of cross-neutralization by SARS patient sera towards SARS-CoV-2 Content: Despite initial findings indicating that SARS-CoV and SARS-CoV-2 are genetically related belonging to the same virus species and that the two viruses used the same entry receptor, angiotensin-converting enzyme 2 (ACE2), our data demonstrated that there is no detectable cross-neutralization by SARS patient sera against SARS-CoV-2. We also found that there are significant levels of neutralizing antibodies in recovered SARS patients 9–17 years after initial infection. These findings will be of significant use in guiding the development of serologic tests, formulating convalescent plasma therapy strategies, and assessing the longevity of protective immunity for SARS-related coronaviruses in general as well as vaccine efficacy.

Title: Lack of cross-neutralization by SARS patient sera towards SARS-CoV-2 Content: Despite initial findings indicating that SARS-CoV and SARS-CoV-2 are genetically related belonging to the same virus species and that the two viruses used the same entry receptor, angiotensin-converting enzyme 2 (ACE2), our data demonstrated that there is no detectable cross-neutralization by SARS patient sera against SARS-CoV-2. We also found that there are significant levels of neutralizing antibodies in recovered SARS patients 9-17 years after initial infection. These findings will be of significant use in guiding the development of serologic tests, formulating convalescent plasma therapy strategies, and assessing the longevity of protective immunity for SARS-related coronaviruses in general as well as vaccine efficacy.

Title: Optimized pseudotyping conditions for the SARS-COV2 Spike glycoprotein Content: The SARS-COV2 Spike glycoprotein is solely responsible for binding to the host cell receptor and facilitating fusion between the viral and host membranes. The ability to generate viral particles pseudotyped with SARS-COV2 Spike is useful for many types of studies, such as characterization of neutralizing antibodies or development of fusion-inhibiting small molecules. Here we characterized the use of a codon-optimized SARS-COV2 Spike glycoprotein for the generation of pseudotyped HIV-1, MLV, and VSV particles. The full-length Spike protein functioned inefficiently with all three systems but was enhanced over 10-fold by deleting the last 19 amino acids of the cytoplasmic tail of Spike. Infection of 293FT target cells was only possible if the cells were engineered to stably express the human ACE-2 receptor, but stably introducing an additional copy of this receptor did not further enhance susceptibility. Stable introduction of the Spike activating protease TMPRSS2 further enhanced susceptibility to infection by 5-10 fold. Substitution of the signal peptide of the Spike protein with an optimal signal peptide did not enhance or reduce infectious particle production. However, modification of a single amino acid in the furin cleavage site of Spike (R682Q) enhanced infectious particle production another 10-fold. With all enhancing elements combined, the titer of pseudotyped particles reached almost 106 infectious particles/ml. Finally, HIV-1 particles pseudotyped with SARS-COV2 Spike was successfully used to detect neutralizing antibodies in plasma from COVID-19 patients, but not plasma from uninfected individuals. Importance When working with pathogenic viruses, it is useful to have rapid quantitative tests for viral infectivity that can be performed without strict biocontainment restrictions. A common way of accomplishing this is to generate viral pseudoparticles that contain the surface glycoprotein from the pathogenic virus incorporated into a replication-defective viral particle that contains a sensitive reporter system. These pseudoparticles enter cells using the glycoprotein from the pathogenic virus leading to a readout for infection. Conditions that block entry of the pathogenic virus, such as neutralizing antibodies, will also block entry of the viral pseudoparticles. However, viral glycoproteins often are not readily suited for generating pseudoparticles. Here we describe a series of modifications that result in the production of relatively high titer SARS-COV2 pseudoparticles that are suitable for detection of neutralizing antibodies from COVID-19 patients.

Title: Emerging Trends in COVID-19 Treatment: Learning from Inflammatory Conditions Associated with Cellular Therapies Content: Coronavirus disease 2019 (SARS-CoV2) is an active global health threat for which treatments are desperately being sought. Even though most people infected experience mild to moderate respiratory symptoms and recover with supportive care, certain vulnerable hosts develop severe clinical deterioration. While several drugs are currently being investigated in clinical trials, there are currently no approved treatments or vaccines for COVID-19 and hence there is an unmet need to explore additional therapeutic options. At least three inflammatory disorders or syndromes associated with immune dysfunction have been described in the context of cellular therapy. Specifically, Cytokine Release Syndrome (CRS), Immune Reconstitution Inflammatory Syndrome (IRIS), and Secondary Hemophagocytic Lymphohistiocytosis (sHLH) all have clinical and laboratory characteristics in common with COVID19 and associated therapies that could be worth testing in the context of clinical trials. Here we discuss these diseases, their management, and potential applications of these treatment in the context of COVID-19. We also discuss current cellular therapies that are being evaluated for the treatment of COVID-19 and/or its associated symptoms.

Title: Emerging trends in COVID-19 treatment: learning from inflammatory conditions associated with cellular therapies Content: Coronavirus disease 2019 (SARS-CoV2) is an active global health threat for which treatments are desperately being sought. Even though most people infected experience mild to moderate respiratory symptoms and recover with supportive care, certain vulnerable hosts develop severe clinical deterioration. While several drugs are currently being investigated in clinical trials, there are currently no approved treatments or vaccines for COVID-19 and hence there is an unmet need to explore additional therapeutic options. At least three inflammatory disorders or syndromes associated with immune dysfunction have been described in the context of cellular therapy. Specifically, Cytokine Release Syndrome (CRS), Immune Reconstitution Inflammatory Syndrome (IRIS), and Secondary Hemophagocytic Lymphohistiocytosis (sHLH) all have clinical and laboratory characteristics in common with COVID19 and associated therapies that could be worth testing in the context of clinical trials. Here we discuss these diseases, their management, and potential applications of these treatment in the context of COVID-19. We also discuss current cellular therapies that are being evaluated for the treatment of COVID-19 and/or its associated symptoms.

Title: NK cells: A double edge sword against SARS-CoV-2 Content: Natural killer (NK) cells are pivotal effectors of the innate immunity protecting an individual from microbes. They are the first line of defense against invading viruses, given their substantial ability to directly target infected cells without the need for specific antigen presentation. By establishing cellular networks with a variety of cell types such as dendritic cells, NK cells can also amplify and modulate antiviral adaptive immune responses. In this review, we will examine the role of NK cells in SARS-COV2 infections causing the ongoing COVID19 pandemic, keeping in mind the controversial role of NK cells specifically in viral respiratory infections and in inflammatory-driven lung damage. We discuss lessons learnt from previous coronavirus outbreaks in humans (caused by SARS-CoV-1 and MERS-COV).

Title: Protective Adaptive Immunity Against Severe Acute Respiratory Syndrome Coronaviruses 2 (SARS-CoV-2) and Implications for Vaccines Content: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an emerging human coronavirus responsible for coronavirus disease 2019 (COVID-19), a predominantly respiratory disease that has become a global pandemic. Millions of people worldwide are suffering from COVID-19, and hundreds of thousands of those infected have died. Nevertheless, many more people who have been infected with SARS-CoV-2 are asymptomatic or suffer a mild disease characterized by dry cough and mild fever. This new pandemic poses a threat to public health on a global scale, and an intervention to prevent continued spread of SARS-CoV-2 virus is of the utmost importance. To assess preventive and therapeutic strategies, it is imperative to understand the pathogenesis and immune response against SARS-CoV-2. In this review, we concentrate on the protective adaptive immune response elicited by this novel coronavirus as well as requirements for a successful vaccine inducing optimal protection.

Title: A Recombinant Vaccine of H5N1 HA1 Fused with Foldon and Human IgG Fc Induced Complete Cross-Clade Protection against Divergent H5N1 Viruses Content: Development of effective vaccines to prevent influenza, particularly highly pathogenic avian influenza (HPAI) caused by influenza A virus (IAV) subtype H5N1, is a challenging goal. In this study, we designed and constructed two recombinant influenza vaccine candidates by fusing hemagglutinin 1 (HA1) fragment of A/Anhui/1/2005(H5N1) to either Fc of human IgG (HA1-Fc) or foldon plus Fc (HA1-Fdc), and evaluated their immune responses and cross-protection against divergent strains of H5N1 virus. Results showed that these two recombinant vaccines induced strong immune responses in the vaccinated mice, which specifically reacted with HA1 proteins and an inactivated heterologous H5N1 virus. Both proteins were able to cross-neutralize infections by one homologous strain (clade 2.3) and four heterologous strains belonging to clades 0, 1, and 2.2 of H5N1 pseudoviruses as well as three heterologous strains (clades 0, 1, and 2.3.4) of H5N1 live virus. Importantly, immunization with these two vaccine candidates, especially HA1-Fdc, provided complete cross-clade protection against high-dose lethal challenge of different strains of H5N1 virus covering clade 0, 1, and 2.3.4 in the tested mouse model. This study suggests that the recombinant fusion proteins, particularly HA1-Fdc, could be developed into an efficacious universal H5N1 influenza vaccine, providing cross-protection against infections by divergent strains of highly pathogenic H5N1 virus.

Title: The Association between Obesity and Poor Outcome after COVID-19 Indicates a Potential Therapeutic Role for Montelukast Content: It is widely believed that infection with the SARS-CoV2 virus triggers a disproportionate immune response which causes a devastating systemic injury, particularly in individuals with obesity, itself a chronic, multi-organ inflammatory disease. Immune cells accumulate in visceral adipose tissue and together with paracrine adipocytes release a wide range of biologically active cytokines (including IL-1β, IL5, IL6 and IL8) that can result in both local, pulmonary and systemic inflammation. A more intense ‘cytokine storm’ is postulated as the mechanism behind the extreme immune response seen in severe COVID-19. It is striking how dangerous the combination of obesity and COVID-19 is, resulting in a greater risk of ICU admission and a higher mortality. Furthermore, patients from a BAME background appear to have increased mortality after SARS-CoV2 infection; they also have a higher prevalence of central obesity and its metabolic complications. In the absence of an effective vaccine, the therapeutic potential of immune-modulating drugs is a priority, but the development of new drugs is expensive and time-consuming. A more pragmatic solution would be to seek to repurpose existing drugs, particularly those that might suppress the heightened cytokine activity seen in obesity, the major risk factor for a poor prognosis in COVID-19. Montelukast is a cysteinyl leukotriene receptor antagonist licensed to treat asthma and allergic rhinitis. It has been shown to diminish pulmonary response to antigen, tissue eosinophilia and IL-5 expression in inflammatory cells. It has also been shown to decrease elevated levels of IL-1β and IL8 in humans with viral upper respiratory tract infections compared with placebo-treated patients. In addition, in silico studies have demonstrated a high binding affinity of the montelukast molecule to the terminal site of the virus’s main protease enzyme which is needed for virus RNA synthesis and replication. Montelukast, which is cheap, safe and widely available would appear to have the potential to be an ideal candidate drug for clinical trials, particularly in early stage disease before irreparable tissue damage has already occurred. HYPOTHESIS: Through a direct anti-viral effect, or by suppression of heightened cytokine release in response to SARS-CoV2, montelukast will reduce the severity of immune-mediated multiorgan damage resulting from COVID-19, particularly in patients with central obesity and metabolic syndrome.

Title: Antibody Profiling and Prevalence in the US population during the SARS-CoV2 Pandemic Content: ABSTRACT Background: Antibody diagnostics play an important role in disease detection and can potentially aid in monitoring of the immune responses to see if an individual has developed immunity. Developing high throughput diagnostics which does not involve handling of infectious material becomes imperative in the case of pandemics such as the recent outbreak of SARS-CoV2. Methods: A protein microarray technology was used to detect the plurality of antibody response to four novel antigens namely S1 glycoprotein, Receptor binding domain (RBD), S2 glycoprotein and Nucleoprotein of the novel coronavirus named SARS-CoV2 using serum samples. A DBS card was additionally used to compare its performance with a venipuncture-based serum separator tube (SST) draw. Results: The three main subclasses of antibodies IgM, IgA and IgG were analyzed to see the variations in immune responses in the affected population and compared to their microbial RT-PCR based NP swab results. The clinical sensitivity and specificity were determined to be 98.1% and 98.6%. In the matrix comparison study, which would enable patients to test without risk of transmitting the virus, DBS matched with higher than 98% accuracy to a venipuncture-based SST collection. Conclusion: Multiplex testing enables higher sensitivity and specificity which is essential while establishing exposure on a population scale. This flexible platform along with a discrete collection methodology would be crucial and broadly useful to scale up testing in current and future pandemics. Minimum sample volume that can be collected using DBS cards can be processed in this multiplex pillar plate format enabling the capacity to provide the reliability of high throughput analyzers while having the ease of collection similar to rapid tests. Keywords: COVID19, SARS-CoV2, Antibody, Multiplex, serology, biomarker, immune modulation, prevalence, high sensitivity, high specificity, Dried blood spot, pandemic, venipuncture

Title: Two complex, adenovirus-based vaccines that together induce immune responses to all four dengue virus serotypes. Content: Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

Title: A case report of possible novel coronavirus 2019 reinfection Content: Since December 2019, COVID-19, the clinical syndrome associated with SARS-CoV-2 infection, has infected more than 6.2 million people and brought the function of the global community to a halt. As the number of patients recovered from COVID-19 rises and the world transitions toward reopening, the question of acquired immunity versus the possibility of reinfection are critical to anticipating future viral spread. Here, we present a case of a patient previously recovered from COVID-19 who re-presents with new respiratory, radiographical, laboratory, and RT-PCR findings concerning for re-infection. We review this case in the context of the evolving discussion and theories surrounding dynamic RT-PCR results, prolonged viral shedding, and the possibility of developed immunity.

Title: Use of pioglitazone in people with type 2 diabetes mellitus with coronavirus disease 2019 (COVID-19): Boon or bane? Content: BACKGROUND AND AIMS: People with type 2 diabetes mellitus (T2DM) have increased morbidity and mortality due to coronavirus disease-19(COVID-19). It has been speculated that use of pioglitazone might increase such risk. The aim of our brief commentary is to review the safety of pioglitazone in people with T2DM and mild/moderate COVID-19. METHODS: We searched PubMed database using specific keywords related to our aims till May 15, 2020. Full text of relevant articles published in English language were retrieved and reviewed. RESULTS: Medications, including pioglitazone, that upregulate tissue expression of angiotensin converting enzyme 2 (ACE2), might have a dual role in COVID-19; on the one hand they might increase risk of infection as SARS-CoV2 uses ACE2 as a coreceptor to enter alveolar cells, but on the other hand, by reducing angiotensin II levels, they can protect against acute lung injury. There is no evidence to date that pioglitazone upregulates ACE2 in the alveolar cells; rather, there is evidence from animal studies of upregulation of ACE2 in insulin sensitive tissues, which might have a protective effect on lung injury. Moreover by moderating the exaggerated host proinflammatory response, pioglitazone can potentially reduce SARS-CoV-2 driven hyperinflammation. CONCLUSIONS: Pioglitazone has more potential for benefit than harm, and can be continued in people with T2DM and mild/moderate COVID-19, unless there are specific contraindications for its use. There is an urgent need to assess clinically relevant outcomes in people with diabetes and COVID-19 based upon baseline antidiabetes therapy, in particular pioglitazone.

Title: Use of pioglitazone in people with type 2 diabetes mellitus with coronavirus disease 2019 (COVID-19): Boon or bane? Content: BACKGROUND AND AIMS People with type 2 diabetes mellitus (T2DM) have increased morbidity and mortality due to coronavirus disease-19(COVID-19). It has been speculated that use of pioglitazone might increase such risk. The aim of our brief commentary is to review the safety of pioglitazone in people with T2DM and mild/moderate COVID-19. METHODS We searched PubMed database using specific keywords related to our aims till May 15, 2020. Full text of relevant articles published in English language were retrieved and reviewed. RESULTS Medications, including pioglitazone, that upregulate tissue expression of angiotensin converting enzyme 2 (ACE2), might have a dual role in COVID-19; on the one hand they might increase risk of infection as SARS-CoV2 uses ACE2 as a coreceptor to enter alveolar cells, but on the other hand, by reducing angiotensin II levels, they can protect against acute lung injury. There is no evidence to date that pioglitazone upregulates ACE2 in the alveolar cells; rather, there is evidence from animal studies of upregulation of ACE2 in insulin sensitive tissues, which might have a protective effect on lung injury. Moreover by moderating the exaggerated host proinflammatory response, pioglitazone can potentially reduce SARS-CoV-2 driven hyperinflammation. CONCLUSIONS Pioglitazone has more potential for benefit than harm, and can be continued in people with T2DM and mild/moderate COVID-19, unless there are specific contraindications for its use. There is an urgent need to assess clinically relevant outcomes in people with diabetes and COVID-19 based upon baseline antidiabetes therapy, in particular pioglitazone.

Title: Electronic nicotine delivery systems (ECs) and COVID-19: the perfect storm for young consumers Content: The COVID-19 pandemic caused a change in our society and put health systems in crisis worldwide. Different risk factors and comorbidities have been found that increase the risk of mortality when acquiring this infection. The use of alternative devices to the cigarette like the electronic cigarettes, the vapers have been studied widely and generators of great controversy since it has been discovered that they also produce different pulmonary affections. When developing the SARS-CoV2 infection, different theories have been generated about the greater predisposition to a worse prognosis of people who use electronic cigarettes; however, the information on this continues in discovery. A group of experts made up of oncologists, infectologists, pulmonologists, and epidemiologists met to review the literature and then generate theories about the impact of electronic cigarettes on SARS-CoV2 infection.

Title: Fighting COVID-19. Content: The current COVID-19 pandemic caused by the novel coronavirus (SARS-CoV2) poses a threat to global health owing to its high rate of spread and severe forms of respiratory infection. The lack of vaccines and antivirals prevents clinical strategies against the disease, creating an emerging need for the development of safe and effective treatments. Strategies for vaccine development include complete vaccines against viruses, subunits, and nucleic acids, but are still in their early stages. Studies carried out to date on possible SARS-CoV2 drug targets highlight glycoprotein S, Mpro (main protease or protease type 3C), and a member of the transmembrane serine protease II families (TMPRSS2). However, due to the pandemic state, priority is given to marketed drugs. These include chloroquine (CQ), hydroxychloroquine (HCQ), nitazoxanide, remdesivir, Lopinavir/ritonavir (LPV / r), in addition to treatment with convalescent plasma. But, therapeutic specific effects against SARS-CoV2 have not yet been verified. Most of the information obtained about treatment is based on preliminary and limited studies. We conclude that, at this time of emergency, the search for new therapies is more urgent due to the need to save lives. Thus, we point out as interesting targets for future more specific research: glycoprotein S, Mpro, and TMPRSS2.

Title: Fighting COVID-19 Content: The current COVID-19 pandemic caused by the novel coronavirus (SARS-CoV2) poses a threat to global health owing to its high rate of spread and severe forms of respiratory infection. The lack of vaccines and antivirals prevents clinical strategies against the disease, creating an emerging need for the development of safe and effective treatments. Strategies for vaccine development include complete vaccines against viruses, subunits, and nucleic acids, but are still in their early stages. Studies carried out to date on possible SARS-CoV2 drug targets highlight glycoprotein S, Mpro (main protease or protease type 3C), and a member of the transmembrane serine protease II families (TMPRSS2). However, due to the pandemic state, priority is given to marketed drugs. These include chloroquine (CQ), hydroxychloroquine (HCQ), nitazoxanide, remdesivir, Lopinavir/ritonavir (LPV / r), in addition to treatment with convalescent plasma. But, therapeutic specific effects against SARS-CoV2 have not yet been verified. Most of the information obtained about treatment is based on preliminary and limited studies. We conclude that, at this time of emergency, the search for new therapies is more urgent due to the need to save lives. Thus, we point out as interesting targets for future more specific research: glycoprotein S, Mpro, and TMPRSS2.

Title: The amount of cytokine-release defines different shades of Sars-Cov2 infection. Content: The recent outbreak of coronavirus disease (COVID 19), spreading from China all around the world in early 2020, has led scientists to investigate the immuno-mediated mechanisms underlying the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) infection. Depending on the amount of cytokines released as the result of the immunological activation induced by SARS-CoV2, three major clinical phenotypes can be identified: "mild",symbolized as a "drizzle" of cytokines, severe as a "storm", and critical as a "hurricane". In patients with mild symptoms, the release of pro-inflammatory cytokines is balanced to obtain a defense response against the virus which is often self-limiting and overcomes without tissue damage. In severe phenotype, resembling a "cytokine-release syndrome", SARS-CoV2 causes the lysis of the immune-mediators leading to a cytokine storm able to induce lung epithelium damage and acute respiratory distress syndrome. In critical patients, the immune response may become uncontrolled, thus the cytokine burst resembles a form of secondary hemophagocytic lymphohistiocytosis which may result in a multi organ failure. In addition to the standard of care, an immune-modulatory therapy tailored to each one of the different phenotypes should be used in order to prevent or reduce the release of cytokines responsible for organ damage and disease progression.

Title: The amount of cytokine-release defines different shades of Sars-Cov2 infection Content: The recent outbreak of coronavirus disease (COVID 19), spreading from China all around the world in early 2020, has led scientists to investigate the immuno-mediated mechanisms underlying the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) infection. Depending on the amount of cytokines released as the result of the immunological activation induced by SARS-CoV2, three major clinical phenotypes can be identified: "mild",symbolized as a "drizzle" of cytokines, severe as a "storm", and critical as a "hurricane". In patients with mild symptoms, the release of pro-inflammatory cytokines is balanced to obtain a defense response against the virus which is often self-limiting and overcomes without tissue damage. In severe phenotype, resembling a "cytokine-release syndrome", SARS-CoV2 causes the lysis of the immune-mediators leading to a cytokine storm able to induce lung epithelium damage and acute respiratory distress syndrome. In critical patients, the immune response may become uncontrolled, thus the cytokine burst resembles a form of secondary hemophagocytic lymphohistiocytosis which may result in a multi organ failure. In addition to the standard of care, an immune-modulatory therapy tailored to each one of the different phenotypes should be used in order to prevent or reduce the release of cytokines responsible for organ damage and disease progression.

Title: Emerging Biomolecular Testing to Assess the Risk of Mortality from COVID-19 Infection Content: [Image: see text] Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 and COVID-19) has produced an unprecedented global pandemic. Though the death rate from COVID-19 infection is ∼2%, many infected people recover at home. Among patients for whom COVID-19 is deadly are those with pre-existing comorbidities. Therefore, identification of populations at highest risk of COVID-19 mortality could significantly improve the capacity of healthcare providers to take early action and minimize the possibility of overwhelming care centers, which in turn would save many lives. Although several approaches have been used/developed (or are being developed/suggested) to diagnose COVID-19 infection, no approach is available/proposed for fast diagnosis of COVID-19 infections likely to be fatal. The central aim of this short perspective is to suggest a few possible nanobased technologies (i.e., protein corona sensor array and magnetic levitation) that could discriminate COVID-19-infected people while still in the early stages of infection who are at high risk of death. Such discrimination technologies would not only be useful in protecting health care centers from becoming overwhelmed but would also provide a powerful tool to better control possible future pandemics with a less social and economic burden.

Title: Emerging Biomolecular Testing to Assess the Risk of Mortality from COVID-19 Infection Content: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 and COVID-19) has produced an unprecedented global pandemic. Though the death rate from COVID-19 infection is â¼2%, many infected people recover at home. Among patients for whom COVID-19 is deadly are those with pre-existing comorbidities. Therefore, identification of populations at highest risk of COVID-19 mortality could significantly improve the capacity of healthcare providers to take early action and minimize the possibility of overwhelming care centers, which in turn would save many lives. Although several approaches have been used/developed (or are being developed/suggested) to diagnose COVID-19 infection, no approach is available/proposed for fast diagnosis of COVID-19 infections likely to be fatal. The central aim of this short perspective is to suggest a few possible nanobased technologies (i.e., protein corona sensor array and magnetic levitation) that could discriminate COVID-19-infected people while still in the early stages of infection who are at high risk of death. Such discrimination technologies would not only be useful in protecting health care centers from becoming overwhelmed but would also provide a powerful tool to better control possible future pandemics with a less social and economic burden.

Title: Recombinant tandem epitope vaccination provides cross protection against Actinobacillus pleuropneumoniae challenge in mice Content: Actinobacillus pleuropneumoniae (A. pleuropneumoniae/APP) is the pathogen that causes porcine contagious pleuropneumonia. Actinobacillus pleuropneumoniae is divided into 18 serovars, and the cross protection efficacy of epitopes is debatable, which has resulted in the slow development of a vaccine. Consequently, epitope-based vaccines conferring Actinobacillus pleuropneumoniae cross protection have rarely been reported. In this study, B cell epitopes in the head domain of trimeric autotransporter adhesin were predicted, and 6 epitopes were selected. Then, the predicted epitopes (Ba1, Bb5, C1, PH1 and PH2) were connected by linkers to construct a recombinant tandem antigen (rta) gene. The RTA protein encoded by the recombinant rta gene was expressed, and finally the ICR mice were immunized with the RTA protein with or without inactivated Actinobacillus pleuropneumoniae (serovars 1 and 5b) and challenged with Actinobacillus pleuropneumoniae to evaluate the protective effect of the epitope-based vaccine and combined vaccine. The mice in the RTA-immunized group and RTA plus inactivated Actinobacillus pleuropneumoniae vaccine group had a significant improvement in clinical symptoms and a higher level of antibody in the serum than those in the control group. The RTA immune group had a 40% survival rate after Actinobacillus pleuropneumoniae infection, whereas the combination of RTA and inactivated Actinobacillus pleuropneumoniae produced very strong cross immune protection in mice, at least 50% (RTA IB1 + C5) and at most 100% (RTA IB5 + C1), whereas no cross immunoprotection was found in the solo Actinobacillus pleuropneumoniae immune group. Overall, the combination of the RTA protein and inactivated bacteria significantly enhanced the cross protection effects. This implies that RTA protein in combination with a suitable inactivated Actinobacillus pleuropneumoniae strain could be a candidate vaccine for porcine contagious pleuropneumonia.

Title: Cross-protective immune responses elicited by a Korean variant of infectious bronchitis virus. Content: Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide. IBVs continuously evolve by developing mutations in antigenic sites; therefore, an IBV vaccine that provides broad cross-protection can be a highly relevant and practical method in IBV control strategies. Although some IBV vaccine strains are known to provide protection against multiple IBV serotypes, in general commercially available IBV vaccine strains provide protection against antigenically related viruses but not distinct heterologous viruses. In the present study we characterized the Korean variant IBV K40/09 strain with regard to its immunogenicity and protective efficacy against seven currently circulating IBV serotypes. Three-week-old specific-pathogen-free chickens were intraocularly immunized with the IBV K40/09 strain at 10(3.5) 50% egg infective dose (EID50). Three weeks after immunization all the birds were challenged with seven different strains at 10(4.5) EID50. Chickens immunized with the IBV K40/09 strain showed significantly high levels of protection against all challenge viruses at the trachea and kidney levels. Our results suggest that IBV K40/09 could be useful to ensure IBV vaccine effectiveness owing to its cross-protective ability. Therefore, the IBV K40/09 strain merits consideration as a vaccine candidate to prevent infection as well as the spread of new IBV strains and many IBV variants that have been reported worldwide.

Title: Does the Bacillus Calmette–Guérin vaccine provide protection from COVID-19? Content: OBJECTIVE: The novel coronavirus pandemic is ravaging throughout the world. It has infected more than 1.2 million people and killed more than 64,000. Frantic research is underway to find prevention and cure. Of late, Bacillus Calmette–Guérin (BCG) has been speculated as a possible protection from COVID-19. We sought to investigate the evidence behind the claim. MATERIAL AND METHODS: Data were collected regarding the total number of COVID-19 cases per million and total number of COVID-19 deaths per million in various countries. The BCG vaccination policies of these countries were also obtained. RESULTS: It was seen that the countries with no universal BCG policy had a mean 1272.9 (median 795) cases per million and 80.7 deaths (median 18) per million population. On the contrary, the countries with a universal BCG vaccination policy had a mean 131.2 (median 40) cases per million and 4 deaths (median 1) per population. The difference is highly significant (P < 0.001). CONCLUSION: The data strongly support the hypothesis that BCG may offer protection from COVID-19. Heterologous protection offered by BCG through production of trained immunity, epigenetic reprogramming of monocytes, non-specific activation of NK cells, and increase of pro-inflammatory cytokines (particularly, tumor necrosis factor [TNF]-alpha and interleukin 1 beta) production may be the mechanism behind its cross- protection against the novel coronavirus.

Title: Protection against homo and hetero-subtypic inﬂuenza A virus by optimized M2e DNA vaccine Content: Current influenza vaccines provide hemagglutinin strain-specific protection, but rarely provide cross-protection against divergent strains. It is, therefore, particularly important to develop a universal vaccine against conserved proteins or conserved regions of the virus. In this study, we used N-terminal extracellular region of the influenza virus M2 protein (M2e) as the target antigen and constructed two optimized M2e DNA vaccines (p-tPA-p3M2e and p-p3M2e) with increased antigenic epitope density and enhanced antigen secretion. Both vaccines induced high M2e-specific humoral and cellular immune responses in the vaccinated mice. These two vaccines also conferred protection against a lethal infection of homo-subtypic H1N1 virus, with p-tPA-p3M2e being the most effective. In addition, p-tPA-p3M2e also showed cross-protection against different subtypes of the influenza virus (H9N2, H6N6, and H10N8) at varying rates (80%, 40%, and 20%, respectively). After passive immunization, M2e DNA vaccine-induced antibodies in the sera provided complete protection against homologous virus challenge. An analysis of the mechanism underlying this immunization-mediated protection indicates that M2e-specific IgG and T-cell immune responses may play critical roles in the prevention of infection and viral clearance. Taken together, our results indicate that this optimized M2e DNA vaccine is a promising candidate for the development of a universal, broad-spectrum influenza virus vaccine.

Title: Cross-reactive neutralization of SARS-CoV-2 by serum antibodies from recovered SARS patients and immunized animals Content: The current COVID-19 pandemic, caused by a novel coronavirus SARS-CoV-2, poses serious threats to public health and social stability, calling for urgent need for vaccines and therapeutics. SARS-CoV-2 is genetically close to SARS-CoV, thus it is important to define the between antigenic cross-reactivity and neutralization. In this study, we firstly analyzed 20 convalescent serum samples collected from SARS-CoV infected individuals during the 2003 SARS outbreak. All patient sera reacted strongly with the S1 subunit and receptor-binding domain (RBD) of SARS-CoV, cross-reacted with the S ectodomain, S1, RBD, and S2 proteins of SARS-CoV-2, and neutralized both SARS-CoV and SARS-CoV-2 S protein-driven infections. Multiple panels of antisera from mice and rabbits immunized with a full-length S and RBD immunogens of SARS-CoV were also characterized, verifying the cross-reactive neutralization against SARS-CoV-2. Interestingly, we found that a palm civet SARS-CoV-derived RBD elicited more potent cross-neutralizing responses in immunized animals than the RBD from a human SARS-CoV strain, informing a strategy to develop a universe vaccine against emerging CoVs. Summary Serum antibodies from SARS-CoV infected patients and immunized animals cross-neutralize SARS-CoV-2 suggests strategies for universe vaccines against emerging CoVs.

Title: Protocol for a multicentre study of nosocomial SARS-CoV2 transmission The NOSO-COR Project Content: Introduction: The newly identified SARS-CoV2 can cause serious acute respiratory infections such as pneumonia with a mortality rate of approximately 2% to 4%. In the current context of high incidence rates of SARS-CoV2 in the community, a significant increase in the rate of nosocomial transmission is expected. The risk of nosocomial transmission could even be higher in low-income countries that have fragile healthcare systems. This protocol is intended to study and document suspected or confirmed cases of nosocomial SARS-CoV2 infection, the clinical spectrum and the determinants (risk factors/protective) at participating hospitals. Methods and analysis: This will be an international multicentre prospective, observational, hospital-based study in adults and children. It will include volunteer patients, care givers and healthcare professionals in France and hospitals affiliated with the GABRIEL network. Demographic and clinical data will be collected using case-report forms designed especially for the purpose of the project. A nasopharyngeal swab will be collected and tested for SARS-CoV2 by RT-PCR. Characteristics of the study participants, the proportion of confirmed nosocomial SARS-CoV2 infections relative to all patients with syndromes suggestive of 2019-nCoV infection will be analysed. Appropriate multivariate modelling will be used to identify the determinants associated with nosocomial onset. Ethics and dissemination: This study was approved by the clinical research and committee of Ile de France V on March 8, 2020. Registration details: The trial was registered in ClinicalTrials (NCT04290780).

Title: Why is SARS-CoV-2 infection more severe in obese men? The gut lymphatics - Lung axis hypothesis Content: Consistent observations report increased severity of SARS-CoV-2 infection in overweight men with cardiovascular factors. As the visceral fat possesses an intense immune activity, is involved in metabolic syndrome and is at the crossroad between the intestines, the systemic circulation and the lung, we hypothesized that it plays a major role in severe forms of SARS-CoV-2 infection. SARS-CoV2 presents the ability to infect epithelial cells of the respiratory tract as well as the intestinal tract. Several factors may increase intestinal permeability including direct enterocyte damage by SARS-CoV2, systemic inflammatory response syndrome (SIRS) and epithelial ischemia secondary to SARS-CoV2- associated endothelial dysfunction. This increase permeability further leads to translocation of microbial components such as MAMPs (microbial-associated molecular pattern), triggering an inflammatory immune response by TLR-expressing cells of the mesentery fat (mostly macrophages and adipocytes). The pro-inflammatory cytokines produced by the mesentery fat mediates systemic inflammation and aggravate acute respiratory distress syndrome (ARDS) through the mesenteric lymph drainage.