The effectiveness of trivalent inactivated influenza vaccine in children over six consecutive influenza seasons

Effectiveness of Trivalent Influenza Vaccine among Children in Two Consecutive Seasons in a Community in Japan

“…However, some vaccine effectiveness studies showed no statistical significance (Ohkuma et al 2002;Maeda et al 2004). One of the strengths of this study is that our investigation had larger sample size (28,884 children-years) than other vaccine effectiveness studies in Japan (346-14,788 children-years) (Ohkuma et al 2002;Maeda et al 2004;Fujieda et al 2008;Ochiai et al 2009;Yamaguchi et al 2010;Katayose et al 2011). To evaluate vaccine effectiveness, the community cohort that involved the entire local city area like this study is essential.…”

“…A significant vaccine efficacy of 52% in influenza A and 59% in influenza B were found during 6 consecutive seasons diagnosed using rapid test kits among children less than 6 years in a community in Japan (Katayose et al 2011). Other studies that estimated vaccine effectiveness among children in Japan during a single influenza season was to be 24%-44% Ochiai et al 2009;Yamaguchi et al 2010).…”

2012/13 influenza vaccine effectiveness against hospitalised influenza A(H1N1)pdm09, A(H3N2) and B: estimates from a European network of hospitals

“…[153,156,157] Several observational studies of TIV VE among children less than 5 years of age have found a VE of 60-85% in seasons where vaccine strains are well-matched to circulating strains, but a VE of 0-60% when vaccines are poorly matched to circulating strains. [158][159][160][161][162][163][164] In addition to the direct protection of children conferred by influenza immunization, limited data indicate that protection of unvaccinated household [165,166] and community contacts [154] may be conferred by immunization of children.…”

Phase I clinical evaluation of seasonal influenza hemagglutinin (HA) DNA vaccine prime followed by trivalent influenza inactivated vaccine (IIV3) boost

“…The control groups were placebo (PBS)–IIV3 and IIV3–IIV3 administered with the same interval. Both controls are of interest because a single injection of IIV3 is the standard for annual influenza vaccinations and because it is known that two injections are needed to confer better immune responses in populations without preexisting immune responses to novel HA antigens [22,23]. …”