Impact of SARS-CoV-2 infection on vaccine-induced immune responses over time

People with previous SARS-CoV-2 infection mount potent immune responses to COVID-19 vaccination, but long-term effects of prior infection on these immune responses are unknown. We investigated the long-term impact of prior SARS-CoV-2 infection on humoral and cellular immune responses in healthcare workers receiving the mRNA BNT162b2 or the adenovirus vectored ChAdOx1 nCoV-19 vaccine. Vaccination with both vaccine platforms resulted in substantially enhanced T cell immune responses, antibody responses to spike and neutralizing antibodies effective against ten SARS-CoV-2 variants following SARS-CoV-2 infection, compared to in naïve individuals. The enhanced immune responses sustained over seven months following vaccination. These findings imply that prior infection should be taken into consideration when planning booster doses and design of current and future COVID-19 vaccine programs.