CD8A and COVID-19: In individuals recovered from COVID-19 without symptoms, CD8+ T cell responses to S, M, and N were detected in 8, 9, and 9 of 13 individuals (Fig. 4b) (fisher’s exact P were 0.090, 1.000, and 0.222 vs healthy controls), with magnitudes of 0.18 (IQR: 0.01–0.31), 0.41 (IQR: 0.06–0.62) and 0.24 (IQR: 0.09–0.82), respectively (Fig. 4b).