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

J Infect Dis. 2022 Oct 17;226(8):1357-1361. doi: 10.1093/infdis/jiab142.


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.

Keywords: COVID-19; SARS-CoV-2; SARS-CoV-2 antibody potency; immunoglobulin; intravenous immune globulin; neutralizing antibodies; plasma; primary immunodeficiency; prophylaxis; secondary immunodeficiency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Serotherapy
  • COVID-19* / therapy
  • Humans
  • Immunization, Passive / methods
  • Immunoglobulins, Intravenous / therapeutic use
  • Pandemics / prevention & control
  • SARS-CoV-2*


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Immunoglobulins, Intravenous