The correlates of protection against illness caused by natural influenza infection in seronegative individuals is important for the design of vaccines capable of conferring immunity against different influenza virus strains. Sridhar et al. now report their analysis of individuals infected by the 2009 H1N1 pandemic influenza virus and show that the presence of pre-existing CD8+ T cell responses to conserved influenza epitopes is associated with reduced severity of illness. The findings support the importance of developing universal influenza vaccines that are capable of inducing crossreactive T cell responses to mitigate influenza illness.
- Saranya Sridhar
- Shaima Begom
- Ajit Lalvani
