Rapidly Increasing Severe Acute Respiratory Syndrome Coronavirus 2 Neutralization by Intravenous Immunoglobulins Produced From Plasma Collected During the 2020 Pandemic

Immunoglobulin lots (N = 176) released since March 2020 were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies, with first positive results for September 2020 lots (mean, 1.7 IU/mL; 46% of lots positive). From there, values steadily increased, in correlation with the cumulative coronavirus disease 2019 (COVID-19) incidence, to reach a mean of 31.2 IU/mL and 93% of lots positive by January 2021. Extrapolating the correlation, immunoglobulins could reach an anti-SARS-CoV-2 potency of approximately 345 IU/mL by July 2021. At that stage, prophylactic immunoglobulin treatment for primary/secondary immunodeficiency could contain similar doses of anti-SARS-CoV-2 as convalescent plasma that is used for treatment of COVID-19. The ongoing COVID-19 pandemic has resulted in seroconversion of a significant proportion of the US plasma donor population, and thus severe acute respiratory syndrome coronavirus 2 neutralizing antibodies are now present in commercial immunoglobulin lots fractionated from US-sourced plasma.

Automated summary

The study found that the levels of SARS-CoV-2 neutralizing antibodies in immunoglobulin lots released since March 2020 have been steadily increasing, reaching a high level by January 2021. It is projected that by July 2021, the anti-SARS-CoV-2 potency in immunoglobulins could further enhance.