AUTHOR=Gomaa Mokhtar R. , Kandeil Ahmed , Mostafa Ahmed , Roshdy Wael H. , Kayed Ahmed E. , Shehata Mahmoud , Kutkat Omnia , Moatasim Yassmin , El Taweel Ahmed , Mahmoud Sara H. , Kamel Mina Nabil , Abo Shama Noura M. , El Sayes Mohamed , El-Shesheny Rabeh , Bakheet Osama H. , Elgohary Mohamed A. , Elbadry Mohamed , Nassif Naguib N. , Ahmed Salwa H. , Abdel Messih Ibrahim Y. , Kayali Ghazi , Ali Mohamed A. 

TITLE=Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 Neutralizing Antibodies in Egyptian Convalescent Plasma Donors

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.596851

DOI=10.3389/fmicb.2020.596851

ISSN=1664-302X

ABSTRACT=Using convalescent plasma as immunotherapy is an old method for treatment of infectious diseases. Several countries have recently allowed the use of such therapy for the treatment of COVID-19 patients especially those who are critically ill. A similar program is currently being tested in Egypt. Here, we tested 227 plasma samples from convalescent donors in Egypt for neutralizing antibodies against SARS-CoV-2 using a microneutralization assay. A third of the tested samples did not have antibody titers and 58% had titers between 1:10 and 1:80. Only 12% had titers > 1:160. We also compared microneutralization assays using different virus concentrations, a plaque reduction neutralization assays (PRNT), and a chemiluminescence assay that measures IgG binding to N and S proteins of SARS-CoV-2. Our results indicated that a microneutralization assay using 100 TCID50/mL provides comparable results to PRNT and allows for high throughput testing.