This observer-blind , randomized study in children 10-17 years of age assessed whether the hemagglutination inhibition ( HI ) antibody responses elicited by H1N1/2009 vaccines adjuvanted with AS03 ( an adjuvant system containing - tocopherol and squalene in an oil-in-water emulsion ) or without adjuvant , met the European regulatory immunogenicity criteria at Days 21 and 182 .