Impact of Preexisting Anti-Adenovirus 26 Humoral Immunity on Immunogenicity of the Ad26.COV2.S Coronavirus Disease 2019 Vaccine

J Infect Dis. 2022 Sep 21;226(6):979-982. doi: 10.1093/infdis/jiac142.

Abstract

This secondary analysis of the phase 3 ENSEMBLE trial (NCT04505722) assessed the impact of preexisting humoral immunity to adenovirus 26 (Ad26) on the immunogenicity of Ad26.COV2.S-elicited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody levels in 380 participants in Brazil, South Africa, and the United States. Among those vaccinated in Brazil and South Africa, 31% and 66%, respectively, had prevaccination serum-neutralizing activity against Ad26, with little preexisting immunity detected in the United States. Vaccine recipients in each country had similar postvaccination spike (S) protein-binding antibody levels, indicating that baseline immunity to Ad26 has no clear impact on vaccine-induced immune responses.

Keywords: Ad26.COV2.S; COVID-19; SARS-CoV-2; preexisting immunity; vaccine.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Ad26COVS1
  • Adenoviridae
  • Adenoviridae Infections*
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Vaccines
  • COVID-19* / prevention & control
  • Genetic Vectors
  • Humans
  • Immunity, Cellular
  • Immunity, Humoral
  • Immunogenicity, Vaccine
  • SARS-CoV-2

Substances

  • Ad26COVS1
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Vaccines