Influenza viruses and cross-reactivity in healthy adults: Humoral and cellular immunity induced by seasonal 2007/2008 influenza vaccination against vaccine antigens and 2009 A(H1N1) pandemic influenza virus

► Humoral and cellular immune responses after seasonal 2007/2008 influenza vaccination. ► Significant homologous humoral and cellular immunity induced against vaccine antigens. ► Cross-reactive cellular responses, but not humoral against new pandemic virus.