The priming effect of previous natural pandemic H1N1 infection on the immunogenicity to subsequent 2010-2011 influenza vaccination in children: a prospective cohort study

Abstract

After a worldwide pandemic influenza A H1N1(H1N1 pdm09) virus infection in 2009, seasonal influenza vaccines contain the A/California/7/2009 (H1N1)-like strain. Immunogenicity studies of pandemic H1N1 influenza vaccines and seasonal influenza vaccines including the A/California/7/2009 (H1N1)-like strain have been carried out globally. Although the pandemic influenza vaccines played some role in the elimination of H1N1 pdm09 influenza, H1N1 pdm09 influenza natural infection may contribute to the acquisition of herd immunity. The 2009 pandemic infection provided an opportunity to study the influence of natural infection on the immune responses.