CD8A and infection: After 721 days, 26 of 37 (70.3%) participants showed CD8+ T-cell responses, whereas “group A” (participants with only one infection (n = 20)) had a lower percentage of T-cell responders with 60% (12 of 20) than “group B” (participants with two infections and reinfection in 2022 (n = 15)) with 86.7% (13 of 15) (Figure A5).