The adjuvants MF59 and LT-K63 enhance the mucosal and systemic immunogenicity of subunit influenza vaccine administered intranasally in mice

Commercial influenza vaccines generate serum antibody, but not local IgA. I nfluenza vaccines that induce both serum and secretory antibody are more li kely to protect against infection and disease progression. The adjuvants MF 59 and LT-K63 were tested intramuscularly and intranasally with subunit HA. In naive mice, intranasal adjuvant effect was more apparent when included with the first than second immunization. In previously infected mice, intra nasal adjuvants had little effect on serum antibodies and were most effecti ve for nasal antibodies after the second immunization. Overall, both adjuva nts enhanced anti-HA IgA and IgG by intranasal vaccination whereas, by intr amuscular vaccination, they only enhanced serum IgG. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.