This study examined the impact of the COVID‐19 vaccine on the induction of the humoral and cellular responses in eight healthy donors who had no history of COVID‐19, were seronegative for SARS‐CoV‐2 antibodies, and showed no or minimal CD8+ T cell reactivity to SARS‐CoV‐2 spike glycoprotein‐derived peptides before the vaccination. Here, CD8A is linked to COVID-19.