T-cell immunity against the A(H1N1) 2009 pandemic virus

Abstract

The sudden emergence of the novel reassortant A(H1N1) 2009 influenza virus led to rapid global spread, due to minimal pre-existing antibody levels in those born after 1950. Memory T cells specific for more conserved viral peptides elicit broad immunity and can promote more rapid recovery. However, mutations within T-cell immunogenic peptides occur, although less commonly than at antibody-binding sites. Comparison of human T-cell peptides between the pandemic H1N1 2009 and seasonal strains showed 50–70% conservation, depending on the particular virus protein and influenza strains. Experimental analysis demonstrated cross-recognition of some T-cell epitopes (for example, HLA-A2+M158-66), altho..