The positive correlation between functional α-CCCs/SARS-CoV-2 cross-reactive memory CD4+ and CD8+ T cells and better disease outcomes in asymptomatic COVID-19 patients supports the importance of developing CoV vaccines that cross-recognize functional α-CCCs/SARS-CoV-2 cross-reactive memory CD4+ and CD8+ T cells (70–72). Here, CD4 is linked to COVID-19.