This study investigated how SARS-CoV-2 infection severity impacts subsequent vaccine-induced immune responses. Researchers assessed humoral and cellular immune responses in 35 individuals recovering from COVID-19 after receiving two vaccine doses. Individuals were categorized into asymptomatic/mild (n=14) and moderate/severe (n=21) infection groups. Results showed that most subjects had robust immune responses after the first dose, with marginal increases after the second. However, the moderate/severe group maintained stronger responses. Polyfunctional CD8+ T cell responses were mostly limited to the moderate/severe group. The study concludes that infection severity should be considered when planning COVID-19 vaccination.

Kayla A. Holder, Danielle P. Ings, Debbie O. A. Harmun, Rodney S. Russell, Michael D. Grant