T Cell Responses to SARS-CoV-2

A large body of evidence generated in the last two and a half years addresses the roles of T cells in SARS-CoV-2 infection and following vaccination. Infection or vaccination induces multi-epitope CD4 and CD8 T cell responses with polyfunctionality. Early T cell responses have been associated with mild COVID-19 outcomes. In concert with animal model data, these results suggest that while antibody responses are key to prevent infection, T cell responses may also play valuable roles in reducing disease severity and controlling infection. Tcell memory after vaccination is sustained for at least six months. While neutralizing antibody responses are impacted by SARS-CoV-2 variants, most CD4 and CD8 T cell responses are preserved. This review highlights the extensive progress made, and the data and knowledge gaps that remain, in our understanding of T cell responses to SARS-CoV-2 and COVID-19 vaccines.

Automated summary

A substantial amount of evidence from the past two and a half years has shown the significant roles T cells play in SARS-CoV-2 infection and post-vaccination. Infection or vaccination triggers multi-epitope CD4 and CD8 T cell responses with polyfunctionality. Early T cell responses are associated with mild COVID-19 outcomes. Alongside animal model data, these findings suggest that while antibody responses are crucial in preventing infection, T cell responses also contribute to reducing disease severity and controlling infection. T cell memory following vaccination lasts for at least six months. Although SARS-CoV-2 variants affect neutralizing antibody responses, most CD4 and CD8 T cell responses are preserved. This review highlights the extensive progress made, as well as the remaining data and knowledge gaps, in understanding T cell responses to SARS-CoV-2 and COVID-19 vaccines.