Emerging Blockininfectious Blockindiseases Blockin@bullet Blockin Feasibility of Using Convalescent Plasma Immunotherapy for Mers-cov Infection, Saudi Arabia

RESEARCH We explored the feasibility of collecting convalescent plasma for passive immunotherapy of Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using ELI-SA to screen serum samples from 443 potential plasma donors: 196 patients with suspected or laboratory-confirmed MERS-CoV infection, 230 healthcare workers, and 17 household contacts exposed to MERS-CoV. ELISA-reactive samples BLOCKINwere BLOCKINfurther BLOCKINtested BLOCKINby BLOCKINindirect BLOCKINfluorescent BLOCKINantibody and microneutralization assays. Of the 443 tested samples, 12 BLOCKIN(2.7%) BLOCKINhad BLOCKINa BLOCKINreactive BLOCKINELISA BLOCKINresult, BLOCKINand BLOCKIN9 BLOCKINof BLOCKINthe BLOCKIN12 BLOCKINhad reactive indirect fluorescent antibody and microneutraliza-tion assay titers. Undertaking clinical trials of convalescent plasma for passive immunotherapy of MERS-CoV infection may be feasible, but such trials would be challenging because BLOCKINof BLOCKINthe BLOCKINsmall BLOCKINpool BLOCKINof BLOCKINpotential BLOCKINdonors BLOCKINwith BLOCKINsufficiently high antibody titers. Alternative strategies to identify convalescent plasma donors with adequate antibody titers should be explored, including the sampling of serum from patients with more severe disease and sampling at earlier points during illness. M iddle East respiratory syndrome coronavirus (MERS-CoV) was initially identified in September 2012 when a patient in Saudi Arabia with a severe, acute respiratory infection and acute renal failure died (1). As of June 19, 2016, more than 1,733 MERS-CoV cases and at least 628 associated deaths had been identified; >80% of the cases occurred in Saudi Arabia (2). More than 20 countries outside of the Arabian Peninsula have reported MERS-CoV cases, and the 2015 outbreak in South Korea with attendant mortality has reinforced concerns about international outbreaks (3). No specific treatment has been proven effective for MERS-CoV infection. Convalescent plasma containing MERS-CoV–specif-ic antibodies from recovered patients has been suggested as a potential therapy for infected persons (4). Convalescent plasma has been used to treat several other viral infections, including those caused by the severe acute respiratory syndrome coronavirus (SARS-CoV), avian influenza A(H5N1) virus, and influenza A(H1N1)pdm09 virus (5–10). A recent metaanalysis of studies using passive immunotherapy for treatment of severe acute respiratory infections of viral etiology suggests that the timely use of convalescent blood products, particularly those with neutralizing antibodies, results in a reduced death rate (11). Public Health England and ISARIC (the International Severe Acute Respiratory and Emerging Infection Consortium) published a decision-making support tool on potential therapies for MERS-CoV that highlights convalescent plasma and other neutralizing antibody–containing immu-notherapeutics (e.g., hyperimmune immunoglobulins and monoclonal antibodies) as the most promising potential treatments for serious MERS-CoV illness and deserving of evaluation in human clinical trial(s) (4). …