Early and Longitudinal Humoral Response to the SARS-CoV-2 mRNA BNT162b2 Vaccine in Healthcare Workers: Significance of BMI, Adipose Tissue and Muscle Mass on Long-Lasting Post-Vaccinal Immunity

Abstract

Background: This study aimed to investigate the early and longitudinal humoral response in Healthcare Workers (HCWs) after two doses of the BNT162b2 vaccine and to assess the association between metabolic and anthropometric parameters and the humoral response after vaccination. Methods: The study included 243 fully vaccinated HCWs: 25.50% previously infected with SARS-CoV-2 (with prior history of COVID-19—PH) and 74.40%—uninfected, seronegative before the first vaccination (with no prior history of COVID-19—NPH). IgG antibodies were measured, and sera were collected: prior to the vaccination, 21 days after the first dose, and 14 days and 8 months after the second dose. Results: 21 days after the first dose, 90.95% of individuals were seropositive; 14 days after the second dose, persistent immunity was observed in 99.18% HCWs, 8 months after complete vaccination—in 61.73%. Statistical analysis revealed that HCWs with PH had a greater chance of maintaining a humoral response beyond eight months after vaccination. Increased muscle mass, decreased fat mass, and younger age may positively affect long-term immunity. Smokers have a reduced chance of developing immunity compared to non-smokers. Conclusions: Fully vaccinated HCWs with PH are more likely to be seropositive than fully inoculated volunteers with NPH.

The Antibody Response to the BNT162b2 mRNA COVID-19 Booster in Healthcare Workers: Association between the IgG Antibody Titers and Anthropometric and Body Composition Parameters

“…The booster again elucidated a humoral response, resulting in positive values of anti-SARS-CoV-2 IgG titers (≥10 AU/mL) in all study participants. However, the mean IgG antibody titer after the third dose was about 3-fold lower compared to the results obtained after administration of the second vaccine dose described in our previous study [ 16 ]. Contrary results were obtained by Skorupa et al, who reported significantly higher levels of anti-SARS-CoV-2 IgG antibodies after the BNT162b2 booster compared to those achieved after the second dose [ 31 ].…”

“…We investigated the IgG antibody-mediated response to three doses of the BNT162b2 vaccine, focusing particularly on a booster-induced response. Interestingly, the most significant increase in anti-SARS-CoV-2 IgG antibody titers on the timeline was observed after administration of the second vaccine dose (early follow-up), as described previously [ 16 ]. At that measurement point, only two participants had non-reactive values of anti-SARS-CoV-2 IgG titers.…”

“…The concept of this study was based on the pilot research conducted by the authors, aiming to investigate the humoral response of 243 HCWs on the timeline and factors affecting IgG titers during and after administration of a two-dose regimen of BNT162b2 vaccine [ 16 ].…”

“…The results were defined according to the manufacturer’s instructions as reactive for SARS-CoV-2 (seropositive) when the titer of IgG against RBD of the S1 protein was ≥10.00 AU/mL and as non-reactive (seronegative) when the value of antibodies was <10.00 AU/mL. Our pilot study described the research methodology in detail [ 16 ].…”

“…The research methodology using TANITA was described in detail in our previous paper [ 16 ]. The measurements were conducted following the manufacturer’s instructions and by the same study team members.…”