IGHG3 and COVID-19: Interestingly, in the COVID-19 patients, we observed high correlations between the NAbs and the S RBD-specific IgG1 antibodies against the Wuhan strain (ρ = 0.85, P < 0.001) and the Omicron variant (ρ = 0.90, P < 0.001) (Fig. 7C and G) as well as the S RBD-specific IgG3 antibodies against the Wuhan strain (ρ = 0.72, P = 0.008) and the Omicron variant (ρ = 0.88, P < 0.001) (Fig. 7D and H).