The antibody landscapes against Group 1 and 2 influenza virus hemagglutinin following AS03 and MF59 adjuvanted H5N1 vaccination

ABSTRACT Current seasonal and pre-pandemic influenza vaccines induce short-lived predominantly strain-specific and limited heterosubtypic responses. To better understand how vaccine adjuvants AS03 and MF59 may provide improved antibody responses to vaccination, we interrogated serum from subjects who received 2 doses of inactivated monovalent influenza A/Indonesia/05/2005 vaccine with or without AS03 or MF59 using hemagglutinin (HA) microarrays. The arrays were designed to reflect both full length and globular head HA proteins derived from 17 influenza A subtypes (H1 to H16 and H18) and influenza B strains. We observed significantly increased strain-specific and broad homo- and hetero-subtypic antibody responses with both AS03 and MF59 adjuvanted vaccination with AS03 achieving a higher titer and breadth of IgG responses relative to MF59. Adjuvanted vaccine was also associated with the elicitation of stalk directed antibody. Finally, we established good correlation of the array antibody responses to H5 antigens with standard hemagglutination inhibition and microneutralization titers.