Conversely, the frequencies of CD4+ effector cells differed (Figure 5C): the amount of specific AIM+IFNγ+ and AIM+IFNγ+IL-2+TNFα+ (triple+) CD4+ T cells were lower in COVID-19-naive older participants than in COVID-19-naive young adults (Figure 5D). This evidence concerns the gene CD4 and COVID-19.