Adjuvanted influenza vaccine.

Adjuvanted influenza vaccine is composed of 2 type A and 1 type B inactivated influenza subunits combined with an oil-and-water emulsion (MF59). Each dose contains 15microg haemagglutinin per strain. Adjuvanted influenza vaccine was immunogenic in elderly vaccinees and in younger adults after 1 to 3 consecutive annual injections. According to studies available to date, the adjuvanted vaccine was more immunogenic than the nonadjuvanted subunit or split virus vaccines and the virosomal vaccine for 1 to 3 of the 3 strains tested per injection. The immunogenic effect generally persisted for longer after the adjuvanted vaccine than the nonadjuvanted subunit vaccine in elderly recipients. The adjuvanted vaccine also appeared to be more effective than the nonadjuvanted subunit vaccine against antigenically different heterovariant strains in elderly vaccinees. The 28-day seroprotection rate in 4 studies was significantly greater after the adjuvanted vaccine for 1 or 2 of the 3 strains tested compared with the nonadjuvanted subunit vaccine and the virosomal vaccine and for 1 of 3 strains compared with the split virus vaccine. The incidence of systemic adverse events was generally low. Local reactions such as pain, erythema and induration occurred more frequently with the adjuvanted than the 2 nonadjuvanted or the virosomal vaccines; however, these were mild and transient.