Influenza Virus Specific CD8+T Cells Exacerbate Infection Following High Dose Influenza Challenge of Aged Mice

Abstract

Influenza viruses cause severe illnesses and death, mainly in the aged population. Protection afforded by licensed vaccines through subtype-specific neutralizing antibodies is incomplete, especially when the vaccine antigens fail to closely match those of the circulating viral strains. Efforts are underway to generate a so-called universal influenza vaccine expressing conserved viral sequences that induce broad protection to multiple strains of influenza virus through the induction of CD8+T cells. Here we assess the effect of a potent antiviral CD8+T cell response on influenza virus infection of young and aged mice. Our results show that CD8+T cell-inducing vaccines can provide some protection to young mice, but they exacerbate influenza virus-associated disease in aged mice, causing extensive lung pathology and death.