In this randomized , observer-blinded study , adults @ years of age ( n = @ ) received @ or @ g hemagglutinin antigen ( HA ) of an AS@-adjuvanted ( AS@A or AS@B ) A/Indonesia/@ / @ H@N@ ( subclade @ ) vaccine ( priming ) , followed by the same HA dose of AS@-adjuvanted A/turkey/Turkey / @/@ H@N@ ( clade @ ) influenza vaccine as a booster @ or @ months after priming ; an unprimed group received placebo at Day @ , and @ g HA of AS@A-adjuvanted booster vaccine at @ and @ months .