In three patients following infection with different coronaviruses, the CMIA showed a S/C result of 0.4 (infection with RCHKU1; SARS-CoV-2 ELISA IgG 0.1; IgA 0.3), 0.5 (infection with RCOC43; SARS-CoV-2 ELISA IgG 0.1; IgA 0.1), and 0.1 (infection with RC229E; SARS-CoV-2 ELISA IgG 0.7; IgA 4.1), whereas the other samples did not reveal a detectable signal. The gene discussed is CD79A; the disease is infection.