CD4 and infection: As discussed previously, the different vaccines induce a different breadth of response, most notably with mRNA vaccines (BNT162b2 and mRNA-1273) only inducing spike specific CD4+ and CD8+ T cell responses92 whereas infection induces CD4+ and CD8+ T cell responses to structural and non-structural proteins across the whole SARS-CoV-2 genome.55 101 115