The recent COVID-19 pandemic left behind the lingering question of whether new variants of concern might cause further waves of infection. So, it is important to investigate the long-term protection provided by vaccination or exposure to the SARS-CoV-2 virus.
T cells are key players in the immune response to viral infection, forming a memory to the virus so that recurrent infections can be more rapidly cleared. In this study, the research team compared the long-term memory T-cell responses following infection with the virus itself, followed by subsequent infections and vaccinations.
They identified common public T cell receptors that are used by dominant SARS-CoV-2 T cells, associated with mild disease outcome, and likely play important protective roles in subsequent viral infection events.
Their analysis focused on the specific responses against three SARS-CoV-2 protein targets - responses that have previously been shown to be found in a large proportion of the population. Analysis of the receptors on the surface of the T cells identified specific receptors shared amongst many different individuals, which the researchers found to be associated with mild COVID-19, compared to those without this receptor who had more severe disease. Furthermore, these specific receptors were found in individuals analysed before the COVID-19 pandemic, suggesting their existence before the pandemic may have allowed these cells to respond quicker to the virus once encountered.
Read the full story on the MRC Weatherall Institute of Molecular Medicine (MRC WIMM) website.