It was recently shown that the use of an experimental subunit vaccine protected mice against infection with a human A/H3N2 influenza virus, but consequently affected the induction of heterosubtypic immunity to a highly pathogenic A/H5N1 influenza virus, which was otherwise induced by the A/H3N2 infection. As whole inactivated virus (WIV) vaccines are widely used to protect against seasonal influenza and also contain inner viral proteins such as the nucleoprotein (NP), the potential of a WIV vaccine to induce protective immunity against infection was tested with a homologous A/H3N2 (A/Hong Kong/2/68) and a heterosubtypic A/H5N1 influenza virus (A/Indonesia/5/05). As expected, the vaccine afforded protection against infection with the A/H3N2 virus only. In addition, it was demonstrated that the use of WIV vaccine for protection against A/H3N2 infection affected the induction of heterosubtypic immunity that was otherwise afforded by A/H3N2 influenza virus infection. The reduction in protective immunity correlated with changes in the immunodominance patterns of the CD8+ T-cell responses directed to the epitopes located in the acid polymerase subunit of the viral RNA polymerase (PA224-233) and the NP (NP366-374). In unvaccinated mice that experienced infection with the A/H3N2 influenza virus, the magnitude of the CD8+ T-cell response to both peptides was similar on secondary infection with A/H5N1 influenza virus. In contrast, prior vaccination with WIV affected the immunodominance pattern and skewed the response after infection with influenza virus A/ Indonesia/5/05 towards a dominant NP366-374-specific response. These findings may have implications for vaccination strategies aimed at the induction of protective immunity to seasonal and/or pandemic influenza.

C57BL mouse, CD8+ T lymphocyte, Influenza virus A H3N2, Influenza virus A H5N1, animal, antibody specificity, article, blood, cytology, epitope, female, gamma interferon, germfree animal, immunology, influenza vaccine, lung, mouse, physiology, spleen, vaccination, virology, virus antibody,
Journal of General Virology
Erasmus MC: University Medical Center Rotterdam

Bodewes, R, Kreijtz, J.H.C.M, Hillaire, M.L.B, Geelhoed-Mieras, M.M, Fouchier, R.A.M, Osterhaus, A.D.M.E, & Rimmelzwaan, G.F. (2010). Vaccination with whole inactivated virus vaccine affects the induction of heterosubtypic immunity against influenza virus A/H5N1 and immunodominance of virus-specific CD8+ T-cell responses in mice. Journal of General Virology, 91(7), 1743–1753. doi:10.1099/vir.0.020784-0