THE ADJUVANT MF59 INCREASES THE IMMUNOGENICITY AND PROTECTIVE EFFICACY OF SUBUNIT INFLUENZA VACCINE IN MICE

The immunogenicity and protective efficacy of influenza vaccine with a nd without the adjuvant MF59 was determined in mice. The addition of M F59 significantly increased the antibody response to the vaccine antig ens over a wide dose range. Equivalent antibody titres were seen using 50- to 200-fold lower antigen concentrations when combined with MF59 compared with vaccine alone. The humoral response was sustained for at least 6 months after immunization. The addition of MF59 increased the protective efficacy of the vaccine: the amount of live virus detectab le in the lungs of mice challenged with virus 1-6 months after immuniz ation was reduced and the rate of survival was significantly increased . Influenza vaccine combined with MF59 gave full protection from viral challenge at antigen doses 65- to 80-fold lower than with vaccine alo ne. (C) 1997 Elsevier Science Ltd.