Since influenza vaccines are normally administered every year because of the frequent change in their antigenic composition, the safety and immunogenicity profile of adjuvanted influenza vaccine need to be re-evaluated after repeated vaccine administration. In this study, subjects previously vaccinated with Fluarix or the influenza adjuvanted vaccine, will receive a booster dose with the 2006-2007 season's formulations of either Fluarix or the adjuvanted vaccine.