A high vaccination rate of older and particularly chronically ill people against coronavirus disease-2019 (COVID-19) is likely one of the most important factors in containing the pandemic. When Germany's vaccination campaign started on December 2020, vaccination prioritization was initially carried out starting with older population groups. Side effect rates in 1065 individuals who had received the first dose of the messenger ribonucleic acid (mRNA) vaccine BNT162b2 Tozinameran from BioNTech/Pfizer three weeks earlier were examined retrospectively. An age- and gender-graded data analysis showed clear age and gender differences with regard to vaccine-related adverse effects. In 77% of all individuals over 80 years of age, no local or systemic side effects were reported after the first vaccination, whereas in the age group up to 80 years, only 37% showed no side effects. In the whole study population, 64% of females and 73% of males reported no adverse effects. The initial vaccination with mRNA vaccine BNT162b2 shows an overall low profile of side effects. Particularly in those over 80 years, an extraordinarily good tolerance with equally good effectiveness is evident. The sex comparison showed that women suffer more often from adverse vaccination reactions. In order to achieve sufficient herd immunity, both age- and gender-dependent vaccination reactions and any difference in the maintenance of immunity should be considered in future vaccination strategies.
Keywords: COVID-19 vaccination; age- and sex-graded data evaluation; mRNA vaccine BNT162b2; vaccination side effects; vaccination strategy.