At least one Committee for Medicinal Products for Human Use (CHMP) immunogenicity criteria for vaccine approval in the elderly was reached by both vaccines against all the viruses used in the study. All three CHMP criteria were reached against A/California/7/04(H3N2)-like, A/Nepal/921/06(H3N2)-like and A/Brisbane/10/07(H3N2)-like viruses by Intanza庐 15 渭g ID vaccine, while IM vaccination did not meet seroprotection criteria against circulating A/Nepal/921/06(H3N2)-like and A/Brisbane/10/07(H3N2)-like viruses or seroconversion criteria against A/Brisbane/10/07(H3N2)-like viruses.
Post-vaccination HI titer, seroconversion, and seroprotection rates were higher against all viruses in subjects who received Intanza庐 15 渭g. The superiority of the seroprotection rate against the A/Nepal/921/06(H3N2)-like strain attained statistical significance despite the small sample size.
Upon Beyer correction for pre-vaccination status, post-immunization HI titers against A/California/7/04(H3N2)-like and A/Brisbane/10/07(H3N2)-like strains and NT post-immunization titers against A/Wisconsin/67/05(H3N2), A/California/7/04(H3N2)-like, A/Brisbane/10/07(H3N2)-like strains were significantly higher in subjects immunized with Intanza庐 15 渭g than in individuals receiving IM vaccine.
This study, although limited in the size of study population, demonstrated the broader immune response elicited by an ID influenza vaccine vs. a standard IM influenza vaccine against heterologous viruses including field isolates.