In individuals recovered from COVID-19 without symptoms, CD4+ T cell responses to S, M and N were detected in 11, 8 and 6 of 13 individuals (Fig. 3b) (fisher’s exact P were 0.039, 0.090 and 0.669 vs healthy controls) with magnitudes of 0.24 (IQR: 0.19–0.48), 0.16 (IQR: 0.03–0.34) and 0.08 (IQR: 0.01–0.14), respectively (Fig. 3b). The gene discussed is CD4; the disease is COVID-19.