With the exception of the M protein, circulating IgA reactivities to SARS-CoV-2 spike, RBD, and NC proteins positively correlated with the severity of COVID-19 in 8-month samples, but not in 12-month samples, and the overall binding response of IgA was weaker than that of IgG (Supplementary Figure S1, middle column). The gene discussed is CD79A; the disease is COVID-19.