Deciphering influenza B virus-derived peptides and their presentation by HLA class I molecules.

Despite influenza vaccines being widely available, influenza still causes significant morbidity and mortality annually. Vaccines typically induce humoral-mediated protection against rapidly mutating surface glycoproteins, necessitating that they be updated and administered each year. In contrast, CD8+ T cells, which can control and clear viral infections, can recognise more conserved viral epitopes. Therefore, there is considerable interest in understanding CD8+ T cell responses to influenza virus for the development of future vaccines and therapeutics. Although Alphainfluenzavirus influenzae (FLUAV) and Betainfluenzavirus influenzae (FLUBV) co-circulate in humans and both contribute to seasonal epidemics, there is limited data regarding CD8+ T cell responses to FLUBV. This knowledge gap spans both immunological and molecular insights. In the present review, we summarise the current knowledge of FLUBV-derived CD8+ T cell epitopes at both cellular and molecular levels, in comparison with FLUAV. Collectively, this highlights the limited data available on FLUBV, despite its significant role in human influenza infections.