No significant influence of pre-vaccination antipyretic use on specific antibody response to a BNT162b2 vaccine booster against COVID-19

•The influence of antipyretic use before a BNT162b2 booster is of concern.•Anti-spike IgG titer and adverse reactions were compared by pre/non antipyretic use.•The geometric mean IgG titer was comparable for the cases and controls.•The frequency and severity of adverse reactions were also comparable.•Consistent results were obtained after propensity score matching. The relation between pre-vaccination antipyretic use and antibody responses to SARS-CoV-2 vaccination has been unclear. We measured the pre- and post-BNT162b2 booster spike-specific IgG titers and recorded antipyretic use and adverse reactions for SARS-CoV-2-naive hospital healthcare workers. The data of 20 cases who used antipyretics within 24 h before vaccination were compared to that of 281 controls. The post-booster geometric mean IgG titers were 15,559 AU/mL (95 % CI, 11,474–21,203) for the cases and 16,850 AU/mL (95 % CI, 15,563–18,243) for the controls (p = 0.622). No significant reduction in the frequency or severity of any of the solicited adverse reactions was found for the cases. Similar results were obtained after adjustment with propensity-score matching for demographic characteristics, baseline IgG titer, and post-vaccination antipyretic use. Antipyretic use within 24 h before vaccination would not affect mRNA COVID-19 vaccine-induced specific antibody responses and that postponement of vaccination due to pre-vaccination antipyretic use would be unnecessary.