The Effect of Third Dose of Pfizer/BioNTech and Moderna COVID-19 mRNA Vaccines on IgG Antibody Titers

Thao A Khuc; Gregery Pequeno; Monica Betancourt-Garcia; Adrienne M Casciato; Marissa Gomez-Martinez; Carlos D Arroyo; Bill D Pope 3rd; Shravan Narmala; Sohail Rao

doi:10.7759/cureus.41696

The Effect of Third Dose of Pfizer/BioNTech and Moderna COVID-19 mRNA Vaccines on IgG Antibody Titers

Cureus. 2023 Jul 11;15(7):e41696. doi: 10.7759/cureus.41696. eCollection 2023 Jul.

Authors

Thao A Khuc¹, Gregery Pequeno¹, Monica Betancourt-Garcia², Adrienne M Casciato¹, Marissa Gomez-Martinez³, Carlos D Arroyo¹, Bill D Pope 3rd⁴, Shravan Narmala⁵, Sohail Rao¹

Affiliations

¹ Medicine, Doctor's Hospital Renaissance (DHR) Health Institute for Research and Development, Edinburg, USA.
² Center of Excellence for Trauma Research in the Border Region, Doctor's Hospital Renaissance (DHR) Health Institute for Research and Development, Edinburg, USA.
³ Family Medicine, Doctor's Hospital Renaissance (DHR) Health Institute for Research and Development, Edinburg, USA.
⁴ Medicine, University of Texas Rio Grande Valley School of Medicine, Edinburg, USA.
⁵ Hematology and Oncology, Doctor's Hospital Renaissance (DHR) Health, Edinburg, USA.

Abstract

With the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the Centers for Disease Control and Prevention (CDC) authorized the third dose of the Pfizer-BioNTech (BNT162b2) vaccine with the rationale for prolonged elevation of anti-SARS-CoV-2 antibody titers and protection against the SARS-CoV-2 virus. To better understand how administration of the third dose of the Pfizer/BioNTech coronavirus disease 2019 (COVID-19) vaccine affects the incidence and severity of SARS-CoV-2 infections, we administered the third dose of the Pfizer-BioNTech (BNT162b2) to 189 participants. Blood samples were collected from participants during each of their scheduled visits (baseline, week two, week 12, and week 24) and tested for semi-quantitative anti-SARS-CoV-2 immunoglobulin G (IgG) titers. Our results showed that administration of the third dose of the Pfizer-BioNTech (BNT162b2) vaccine elicited elevated anti-SARS-CoV-2 IgG antibodies for the 24-week duration of the study. IgG antibody titers were greatest in week two, and progressively decreased by week 12 and week 24, with statistically significant differences between the IgG antibody titers for each collection date.

Keywords: cdc coronavirus; corona virus disease; coronavirus disease 2019 (covid-19); covid-19; covid-19 vaccine; pfizer vaccine; who coronavirus.

Grants and funding

The COVID-19 HRSA grant was used to pay for the testing supplies used (such as paying the lab fees and phlebotomist for sample obtainment) as well as services.