Isabell Wagenhäuser (Würzburg / DE), Julia Reusch (Würzburg / DE), Juliane Mees (Würzburg / DE), Lukas Bernhard Krone (Oxford / GB; Bern / CH), Carolin Curtaz (Würzburg / DE), Thien-Tri Lam (Würzburg / DE), Alexandra Schubert-Unkmeir (Würzburg / DE), Anna Frey (Würzburg / DE), Lars Dölken (Würzburg / DE), Oliver Kurzai (Würzburg / DE; Jena / DE), Stefan Frantz (Würzburg / DE), Achim Wöckel (Würzburg / DE), Alexander Gabel (Würzburg / DE), Manuel Krone (Würzburg / DE), Nils Petri (Würzburg / DE)
Question
Oral contraceptives profoundly impact various physiological functions, including the immune response. However, the influence of oral contraceptives (OC) on the immunogenicity of vaccinations in general, and in particular the COVID-19 vaccination, is largely unknown. This study explored the effects of OC on the immune response following COVID-19 booster vaccinations.
Methods
From 18 November 2021 to 13 October 2023 the immunogenicity of the third COVID-19 vaccination as booster among 711 female healthcare workers (HCWs) between 18-50 years was assessed as part of the CoVacSer study. Individuals on long-term OC medication were compared to those not taking OCs. Blood serum samples, along with a comprehensive study questionnaire on sociodemographic data, were collected before (pre) and after (post) a third COVID-19 vaccination. Anti-SARS-CoV-2-Spike IgG levels were measured using the SERION ELISA agile SARS-CoV-2 IgG.
Results
19.7% (140/711) reported taking OC regularly. Univariate analysis comparing the groups with and without OC medication, found no differences in Anti-SARS-CoV-2-Spike IgG titres after the third COVID-19 vaccination (p=0.48). Yet, in the univariate analysis the relative increase of IgG levels after the third vaccination was significantly higher in cohort without OC (p=0.02). However, the linear regression model considering the factors smoking, age, BMI, COVID-19 booster vaccine, SARS-CoV-2 infection history and household size did not reveal a significant effect of OC medication on the IgG increase.
Figure 1: Anti-SARS-CoV-2-Spike IgG levels related to the third COVID-19 vaccination separated by OC
BAU/ml = Binding Antibody Units per millilitre
Conclusions
Despite the generally known interaction of OC intake and the immune response in women, our study was the first to investigate the influence of OC on the immunogenicity specifically for COVID-19 vaccination. Despite the large sample size of our study, we found no effect of OCs on antibody titres providing strong evidence that OCs have no influence on the immunogenicity of COVID-19 booster vaccinations.