The Relationship Between SARS-CoV-2 Neutralizing Antibody Titers and Avidity in Plasma Collected From Convalescent Nonvaccinated and Vaccinated Blood Donors

J Infect Dis. 2023 Aug 11;228(3):245-250. doi: 10.1093/infdis/jiad070.

Abstract

Convalescent plasma (CP) treatment of coronavirus disease 2019 (COVID-19) has shown significant therapeutic effect when administered early (eg, Argentinian trial showing reduced hospitalization) but has in general been ineffective (eg, REMAP-CAP trial without improvement during hospitalization). To investigate whether the differences in CP used could explain the different outcomes, we compared neutralizing antibodies, anti-spike IgG, and avidity of CP used in the REMAP-CAP and Argentinian trials and in convalescent vaccinees. We found no difference between the trial plasmas, emphasizing initial patient serostatus as treatment efficacy predictor. By contrast, vaccinee CP showed significantly higher titers and avidity, being preferable for future CP treatment. Clinical Trials Registration. NCT02735707 and NCT04479163.

Keywords: COVID-19; IgG; SARS-CoV-2; avidity; convalescent plasma; neutralizing antibody; treatment.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Blood Donors
  • COVID-19 Serotherapy
  • COVID-19* / therapy
  • Humans
  • Immunization, Passive
  • SARS-CoV-2*

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral

Associated data

  • ClinicalTrials.gov/NCT04479163
  • ClinicalTrials.gov/NCT02735707