Assessing the Progress of Various Novel SARS-CoV-2 Vaccine Tests and Clinical Trials
Authors: Khajenoori Yasmin , Aslam-Mir Ayesha , Ahmadi Arezo , Iwazaki Risa , Puliady Shiv 
Published: August 2020

The SARS-CoV-2 outbreak of winter 2019 and 2020 has boomed into a global pandemic of a highly contagious respiratory illness, COVID-19. This affliction causes severe acute respiratory distress and, for many with pre-existing conditions, can threaten to be fatal. Many pharmaceutical manufacturers have been allowed to accelerate their vaccination development, an otherwise lengthy and several stage process. Vaccines being developed are both novel and traditional; some target the spike protein, an agent in SARS-CoV-2 contagion, as recent studies showed that it produced polyclonal antibody responses and neutralized SARS-CoV-2 S-mediated entry, as well as the receptor binding domain. Animal testing used pre-clinical trial in Sinovac’s PiCoVacc show promise to create SARS-CoV-2–specific antibody responses targeting S-specific and RBD-specific IgG in mice, which is why PiCoVacc was shown to mitigate the severity of the virus’s symptoms in all rhesus macaques tested. Additionally, testing of Novavax’s NVX-CoV2373 used live mice and baboon models and has shown promising results of high affinity antibody responses targeting SARS-CoV-215. In this pre-clinical trial, the spleens of animal models who received NVX-CoV2373 followed by a Matrix-M adjuvant, or an immune response boosting agent, showed increased frequencies of TFH cells and GC B cells, encouraging Novavax to continue into clinical trial stages15. Vaccine candidates have already produced post-clinical trial results. INO-4800, a DNA vaccine made by INOVIO, has passed phase 1 clinical trials, while demonstrating general safety in all volunteers and generating immunological response rates and T cell immune responses in 94% of the participants. Moderna and Pfizer show promise with mRNA vaccines, both for the spike protein and receptor domain12; these follow a novel approach and have currently moved into their phase two trials due to increased immune response and reduced adverse effects initially in clinic; Moderna’s spike protein vaccine showed titers of antibody 2.1 times higher than those convalescent with the 100ug dosage, in addition to elevated T-cell response post inoculation for all tested doses.3, 9 Another vaccine, known as ChAdOx1 nCoV-19, a chimpanzee adenovirus-vectored vaccine, has been tested on 1077 healthy adults through single and double doses. The results have shown that the single dose elicited both humoral and cellular responses against SARS-CoV-2, with a booster immunization augmenting antibody titers. Within the ChAdOx1 nCoV-19 groups, local and systemic reactions were more common5. Patients were randomly assigned single intramuscular injections of ChAdOx1 nCoV-19 at doses of 5 × 1010 viral particles or MenACWY5. After the vaccination procedure, participants were observed in the clinic for 30-50 minutes and asked to take note of any abnormal events during the 28-day follow up period5. Evaluating the adenovirus, mRNA, DNA, inactivated, and subunit vaccines currently in accelerated development by pharmaceutical manufacturers will allow for a comprehensive review of which vaccine is most ready for widespread use and can successfully and safely curtail further spread of SARS-CoV-2.