Lipopeptide vaccines: a strategy for improving protective immunity against influenza

Background: Lipopeptide vaccines containing minimal CTL determinants have been shown to induce CTL responses against a variety of viruses, however, few have been reported to induce viral clearance. This study examines the ability of a lipopeptide vaccine incorporating palmitic acid, a CTL and a helper T cell (TH) determinant from influenza virus, to induce CTL-mediated viral clearing responses. The efficacy of the immunogen was examined after one or two doses, delivered either in the absence of an adjuvant or formulated with either CFA or Montanide ISA-720. Methods: The lipopeptide was administered subcutaneously s.c.) to mice and at different times post-priming, mice were challenged with nonlethal doses of influenza virus and the titres in the lungs determined 5 days later. Results: High levels of anti-viral protection of the lung were achieved when the lipopeptide was administered with or without an adjuvant and only a single dose of vaccine was necessary to elicit long-lived immunity. The best reduction in lung virus titres was obtained when the construct was administered in Montanide ISA-720. Conclusions: These findings demonstrate the ability of T cell-based lipopeptide vaccines to induce effective influenza viral clearing responses, highlighting their potential as an adjunct to vaccines eliciting antibody responses. (C) 2001 Elsevier Science B.V. All rights reserved.