CD4 and infection: In line with this, the percentage frequency of CD4+ T cells that produce IFN-γ, IL-17 or IL-10 in the splenocytes remained low in BA.5 infection as compared to ancestral Wuhan-Hu-1, but were found to be comparable to that of parental B.1.1.529 infected mice (Supplementary Fig. 3b, c).