IMMUNOPOTENTIATION OF HUMORAL AND CELLULAR-RESPONSES TO INACTIVATED INFLUENZA VACCINES BY 2 DIFFERENT ADJUVANTS WITH POTENTIAL FOR HUMAN USE

Two quite different adjuvants, currently under development for use in humans, have been examined for their effects on the magnitude ann type of immunity elicited in response to inactivated influenza vaccine. Im munostimulating complexes (ISCOM(TM) adjuvant) contain the saponin ISC OPREP(TM) 703, ann SPT is an oil-in-water emulsion of squalane, non-io nic block copolymer (L121) and Tween 80. Influenza virus vaccines form ulated in either adjuvant were far superior to the non-adjuvanted aque ous vaccine in eliciting antibody and T-cell responses in mice, partic ularly at lower doses of antigen. In addition, the vaccines containing adjuvant were superior in eliciting protective immunity. One of the s hortcomings of the unadjuvanted inactivated influenza vaccine was its inability to elicit a primary proliferative T-cell response. However, after one dose of either adjuvanted vaccine, strong proliferative resp onses were achieved. We also show that subcutaneous vaccination with i nactivated vaccines is capable of modulating the isotype profile of an tibody secreting cells generated in the lungs of mice in response to i ntranasal challenge with live virus. In this system, the isotype of an tibody elicited after challenge of mice that had received ISCOM vaccin e more closely mimicked that of animals vaccinated with live virus. (C ) 1998 Elsevier Science Ltd. All rights reserved.