ENHANCEMENT OF HUMORAL RESPONSE AGAINST HUMAN INFLUENZA VACCINE WITH THE SIMPLE SUBMICRON OIL WATER EMULSION ADJUVANT MP59/

Human influenza subunit vaccines are not fully protective in either th e very young or elderly populations where risk is greatest. The toe of an adjuvant to enhance antibody titer is an attractive option to incr ease vaccine efficacy. A series of squalene/H2O emulsions stabilized e ither by the amphipathic muramyl peptide MTP-PE (sodium 1',2'-dipalmit oyl-sn-glycero-3'phospho)ethylamide) or by mixtures of the sorbitan ol eate surfactants Tween 80 and Span 85 have been tested as adjuvants wi th influenza vaccine, Combination of influenza vaccine with the Tween/ Span stabilized emulsions has resulted in significantly higher antibod y titers to vaccine in an extensive series of naive animal models, The use of submicron emulsion droplets is significant in determination of adjuvant activity, while the presence of the muramyl peptide is not r equired for adjuvant activity, The 200-300 nm diameter emulsion formul ation MF59 containing only the low toxicity components squalene, Tween 80 and Span 85 has been shown to enhance titers from 5 to 250 times t hat achievable, vith vaccine alone.