Comprehensive analysis of specific and cross-reactive SARS-CoV-2 epitopes reveals functional T cell responses against specific viral regions in essentially all convalescent individuals and a majority of unexposed donors, demonstrating that cross-reactive responses to COVID-19 are widespread.
It is evident from a growing body of research that both CD4+ and CD8+ T cells specific to SARS-CoV-2 arise following COVID-19 and can be sensitively detected during active infection and convalescence. Ex vivo stimulation of patient’s immune cells with peptides derived from SARS-CoV-2 has allowed for the characterization of patient T cell responses that are specific to this virus. Moreover, several studies have provided evidence that a proportion of pre-existing or ‘cross-reactive’ T cells may have arisen from a previous infection with common cold coronaviruses (CCCs).
