The role of adjuvants in vaccines for seasonal and pandemic influenza.

Current seasonal influenza vaccines aim to induce high-titred virus-neutralizing antibody to the viral hemagglutinin (HA), which is the best form of protection against infection, but these vaccines can be poorly efficacious in the elderly and other target groups that rely on them most. Furthermore, little cross-protection is provided against significantly drifted strains and even less against different subtypes of virus with pandemic potential. Adjuvants could theoretically have two different roles in improving control of influenza through vaccination. Firstly, a role in enhancing the antibody response in situations where the split virus preparation is poorly immunogenic or if there is an imperative to provide "dose sparing" in the context mass vaccination with a virus to which the population is immunologically naïve. Secondly, adjuvants could be used to allow induction of additional arms of the immune response that are not stimulated by current split virus vaccines. Briefly reviewed here are our efforts to investigate the role of adjuvants in both these contexts.