T-Cell Responses in Children to Internal Influenza Antigens, 1 Year After Immunization With Pandemic H1N1 Influenza Vaccine, and Response to Revaccination With Seasonal Trivalent–inactivated Influenza Vaccine

During seasonal influenza epidemics, 5-15% of the population are affected with an illness having a nontrivial mortality, morbidity and economic burden. Inactivated influenza vaccines are routinely used to prevent influenza infection, primarily by inducing humoral immunity. In addition, trivalent-inactivated influenza vaccines have previously been shown to boost influenza-specific T-cell responses in a small percentage of adults. We investigate here the influenza-specific T-cell response, in children, 1 year after pandemic H1N1 vaccination and the ability to boost the T-cell response with trivalent-inactivated influenza immunization.