PLoS ONE (Jan 2022)

Effect of the third dose of BNT162b2 vaccine on quantitative SARS-CoV-2 spike 1-2 IgG antibody titers in healthcare personnel.

  • Maria Elena Romero-Ibarguengoitia,
  • Diego Rivera-Salinas,
  • Yodira Guadalupe Hernández-Ruíz,
  • Ana Gabriela Armendariz-Vázquez,
  • Arnulfo González-Cantú,
  • Irene Antonieta Barco-Flores,
  • Rosalinda González-Facio,
  • Laura Patricia Montelongo-Cruz,
  • Gerardo Francisco Del Rio-Parra,
  • Mauricio René Garza-Herrera,
  • Jessica Andrea Leal-Meléndez,
  • Miguel Ángel Sanz-Sánchez

DOI
https://doi.org/10.1371/journal.pone.0263942
Journal volume & issue
Vol. 17, no. 3
p. e0263942

Abstract

Read online

BackgroundVaccination is our main strategy to control SARS-CoV-2 infection. Given the decrease in quantitative SARS-CoV-2 spike 1-2 IgG antibody titers three months after the second BNT162b2 dose, healthcare workers received a third booster six months after completing the original protocol. This study aimed to analyze the quantitative SARS-CoV-2 spike 1-2 IgG antibody titers and the safety of the third dose.Material and methodsA prospective longitudinal cohort study included healthcare workers who received a third booster six months after completing the BNT162b2 regimen. We assessed the quantitative SARS-CoV-2 spike 1-2 IgG antibody titers 21-28 days after the first and second dose, three months after the completed protocol, 1-7 days following the third dose, and 21-28 days after booster administration.ResultsThe cohort comprised 168 participants aged 41(10) years old, 67% of whom were female. The third dose was associated with an increase in quantitative antibody titers, regardless of previous SARS-CoV-2 history. In cases with a negative SARS-CoV-2 history, the median (IQR) antibody titer values increased from 379 (645.4) to 2960 (2010) AU/ml, whereas in cases with a positive SARS-CoV-2 history, from 590 (1262) to 3090 (2080) AU/ml (pConclusionThe third dose applied six months after the original BNT162b2 regimen increased the quantitative SARS-CoV-2 spike 1-2 IgG antibody titers. The booster dose was well tolerated and caused no severe AEFI.