We could not assess neutralizing antibody titers from the convalescent plasma. Plasma with high neutralizing antibody titers is likely to be available from the patients in the convalescent phase recovered from severe infection.20 To use plasma for treatment, a neutralization test is suggested as the optimal assay for assessing proper donor or plasma. However, some studies showed that ELISA IgG correlates well with neutralization titers in MERS cases so that it might be a suitable screening test for plasma donation.2021 In our cases, donors presented bilateral pneumonia in the course of COVID-19 and both showed positive results in the ELISA IgG test for SARS-CoV-2.