Anti-SARS-CoV-2 Immunoglobulin Isotypes, and Neutralization Activity Against Viral Variants, According to BNT162b2-Vaccination and Infection History

Front Immunol. 2021 Dec 17:12:793191. doi: 10.3389/fimmu.2021.793191. eCollection 2021.

Abstract

Purpose: To compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.1.617.2 variants-of-concern, in subjects with different Covid-19 disease and vaccination histories.

Methods: Adult subjects were: 1) Unvaccinated/hospitalized for Covid-19; 2) Covid-19-recovered followed by one BNT162b2 vaccine dose; and 3) Covid-19-naïve/2-dose BNT162b2 vaccinated. Multiplex Luminex® immunoassays measured IgG, IgA, and IgM plasma levels against SARS-CoV-2 receptor-binding domain (RBD), spike-1 (S), and nucleocapsid proteins. Neutralizing activity was determined in Vero E6 cytopathic assays.

Results: Maximum anti-RBD IgG levels were similar in Covid-19‑recovered individuals 8‒10 days after single-dose vaccination and in Covid-19-naïve subjects 7 days after 2nd vaccine dosing; both groups had ≈2‑fold higher anti-RBD IgG levels than Unvaccinated/Covid-19 subjects tracked through 2 weeks post-symptom onset. Anti-S IgG expression patterns were similar to RBD within each group, but with lower signal strengths. Viral antigen-specific IgA and IgM levels were more variable than IgG patterns. Anti-nucleocapsid immunoglobulins were not detected in Covid-19-naïve subjects. Neutralizing activity against the B.1 strain, and Gamma/P.1 and Delta/B.1.617.2 variants, was highest in Covid‑19-recovered/single-dose vaccinated subjects; although neutralization against the Delta variant in this group was only 26% compared to B.1 neutralization, absolute anti-Delta titers suggested maintained protection. Neutralizing titers against the Gamma and Delta variants were 33‒77% and 26‒67%, respectively, versus neutralization against the B.1 strain (100%) in the three groups.

Conclusion: These findings support SARS-CoV-2 mRNA vaccine usefulness regardless of Covid-19 history, and confirm remarkable protection provided by a single vaccine dose in people who have recovered from Covid-19.

Keywords: COVID-19; SARS-CoV-2; bead; coronavirus; fluorescence; multiplex immunoassay; neutralization assay; serological assay.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Antibodies, Neutralizing / immunology*
  • Antibodies, Viral / immunology*
  • BNT162 Vaccine / administration & dosage
  • BNT162 Vaccine / immunology*
  • COVID-19 / immunology*
  • COVID-19 / virology
  • Chlorocebus aethiops
  • Female
  • Humans
  • Immunoassay / methods
  • Immunoglobulin A / blood
  • Immunoglobulin A / immunology
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Immunoglobulin Isotypes / blood
  • Immunoglobulin Isotypes / immunology*
  • Immunoglobulin M / blood
  • Immunoglobulin M / immunology
  • Male
  • Middle Aged
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / immunology*
  • SARS-CoV-2 / physiology
  • Spike Glycoprotein, Coronavirus / immunology
  • Spike Glycoprotein, Coronavirus / metabolism
  • Vaccination / methods
  • Vero Cells

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin Isotypes
  • Immunoglobulin M
  • Spike Glycoprotein, Coronavirus
  • BNT162 Vaccine

Supplementary concepts

  • SARS-CoV-2 variants