Age and sex associations of SARS-CoV-2 antibody responses post BNT162b2 vaccination in healthcare workers: A mixed effects model across two vaccination periods

Abstract

This study aimed to examine the associations with epidemiological, behavioral and clinical parameters of IgG antibody responses against the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after immunization with two doses of the BNT162b2 vaccine in a cohort of healthcare workers (HCWs, n = 439) in Greece. We used a mixed effects model to investigate the potential associations of antibody levels one and three months after vaccination and examined by bootstrapping t-tests the putative effects of gender and age for each period. We also employed exact tests of independence in R × C contingency tables to explore associations between behavioral and gender variables with vaccinations side effects. We found significant differences between males and females as well as between subjects in the youngest (21–30 years) and the older age groups in both study periods. We also detected a decrease in titers with age and time. Males had steeper elimination rates across the age span in both periods, in contrast to females who exhibited a softer elimination titer rate with age in the first period and almost constant titers in the second. Concerning side effects, we found a significant association between pain at the injection site and female sex. Hence, our real-world data analyses revealed potentially important clues into the associations of antibody responses to SARS-CoV-2 spike. We discuss the importance of these findings in view of current mass vaccination perspectives and provide useful clues for the design and optimal timing of booster doses for COVID-19.

Neutralising antibody responses to SARS-CoV-2 omicron among elderly nursing home residents following a booster dose of BNT162b2 vaccine: A community-based, prospective, longitudinal cohort study

“…The over-representation of females among our participants (30 out of 38 individuals) may have also biased our results, as females are known to differ from males in the induction and waning of antibodies, in both infection and vaccination settings. 22 , 33 , 34 We did not have access to nasopharyngeal swabs to measure antibody levels at the site of viral entry and replication. We were thus unable to link breakthrough infections to local levels of antibodies, which might represent a better correlate of protection.…”

Humoral immunoresponse elicited against an adenoviral-based SARS-CoV-2 coronavirus vaccine in elderly patients

“…Although males have been shown in some cases to exhibit reduced humoral immunity after vaccination for, or infection with, SARS-CoV-2 [30,31], due to the crucial role of cellular immunity in defense against this virus, a decrease in specific antibodies should be carefully studied and not immediately assumed as a reduction in protection towards severe COVID-19.…”

“…This increased persistence of SARS-CoV-2 specific antibodies in females, also reported by Søgaard OS [ 28 ], can be explained by the presence of more active B and T cells in older females, resulting in the generation of long-term responses to antigens [ 29 ]. Although males have been shown in some cases to exhibit reduced humoral immunity after vaccination for, or infection with, SARS-CoV-2 [ 30 , 31 ], due to the crucial role of cellular immunity in defense against this virus, a decrease in specific antibodies should be carefully studied and not immediately assumed as a reduction in protection towards severe COVID-19.…”

Measurements of Anti-SARS-CoV-2 Antibody Levels after Vaccination Using a SH-SAW Biosensor

“…The results of this study also suggested that there are individual differences in the antibody response to vaccination. Potential factors are age, gender, and genetics [ 17 ]. Several studies have shown that women and men have an overall similar antibody response after vaccination, however some women have a faster decrease in antibody levels.…”