Efficacy of BNT162b2 vaccine and its correlation with serum vitamin D in staff at the National Comprehensive Cancer Center in Slovakia.

person Jan Slopovsky 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Bratislava, Slovakia info_outline Jan Slopovsky, Silvia Cingelova, Alena Svobodova, Lucia Skokanova-Krempaska, Katarina Rejlekova, Robert Babela, Lubos Drgona, Michal Mego, Martina Vulganova, Juraj Pechan, Patrik Palacka

Authors person Jan Slopovsky 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Bratislava, Slovakia info_outline Jan Slopovsky, Silvia Cingelova, Alena Svobodova, Lucia Skokanova-Krempaska, Katarina Rejlekova, Robert Babela, Lubos Drgona, Michal Mego, Martina Vulganova, Juraj Pechan, Patrik Palacka Organizations 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute, Bratislava, Slovakia, Department of Oncohematology, Faculty of Medicine, Comenius University and National Cancer Institute, Bratislava, Slovakia, Department of Clinical Biochemistry, National Cancer Institute, Bratislava, Slovakia, Hospital Pharmacy, National Cancer Institute, Bratislava, Slovakia, Slovak Medical University and National Cancer Institute, Bratislava, Slovakia, Central-European Biotech Institute, Bratislava, Slovakia, Department of Surgical Oncology, Slovak Medical University and National Cancer Institute, Bratislava, Slovakia, 2nd Department of Oncology, Faculty of Medicine, Comenius University and National Cancer Institute; Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia Abstract Disclosures Research Funding No funding received None. Background: With established efficacy and safety, BNT162b2 was one of the first licensed mRNA vaccines against SARS-CoV-2. However, it is unclear whether vitamin D serum concentrations affect vaccine efficacy after three doses. Methods: This prospective, single-center study included 273 staff members (85.4% females) of the National Cancer Comprehensive Center in Slovakia. Median age of participants was 47 years (range: 22–80) and median body mass index (BMI) was 24.8 (16.3–44.6) kg/m 2 . The primary objective was to determine the efficacy of BNT162b2 defined as no Covid-19 disease ≥7 days after its administration. The secondary objective was to monitor IgG neutralizing antibodies and total vitamin D in serum after vaccination and test the hypothesis on correlation of total vitamin D concentrations with the vaccine efficacy. If appropriate, results were stratified by gender (males vs females) and BMI ( < 30 vs ≥30 kg/m 2 ). Results: At median follow-up of 4.7 (2.9–5.0) months, vaccine efficacy was 86.1%. The most common adverse events (AEs) were injection site pain (73.3%), fatigue (44.0%), and limb pain (33.0%). No grade 3/4 AEs were observed. Median time from vaccine administration to measurement of IgG and vitamin D concentrations was 3.4 (2.1-4.8) months. IgG concentrations were significantly higher in males compared to females, as well as in subjects with high vs low BMI ( p < 0.0004 and p < 0.0001, respectively). Total vitamin D concentrations were significantly lower in individuals with high vs low BMI ( p < 0.0144). No differences in the rate of Covid-19 positivity were identified based on gender, BMI, and total vitamin D concentrations. Conclusions: This study confirmed high efficacy of third dose of the BNT162b2 vaccine with an acceptable safety profile. The vaccine efficacy was not affected by gender, BMI, and total vitamin D concentrations. These results suggest that serum vitamin D monitoring after third BNT162b2 dose is not beneficial for an estimation of its efficacy. This study was supported by the National Cancer Institute, Bratislava, Slovakia & OncoReSearch, Rovinka, Slovakia. Keywords: BNT162b2; total vitamin D; efficacy; safety profile; IgG.