A novel liposomal influenza vaccine (INFLUSOME-VAC) containing hemagglutinin-neuraminidase and IL-2 or GM-CSF induces protective anti-neuraminidase antibodies cross-reacting with a wide spectrum of influenza A viral strains

A liposomal influenza vaccine (INFLUSOME-VAC) was developed with the object ive of overcoming the major drawbacks of the currently used influenza vacci nes: their relatively low efficacy in certain high-risk groups (the elderly , infants, the immunosuppressed) and the need for annual immunization. INFL USOME-VAC consists of liposomes containing the viral surface proteins hemag glutinin (HA) and neuraminidase (NA) derived from various influenza strains and IL-2 or GM-CSF, as an adjuvant. Vaccination of mice showed that, where as conventional vaccines induced a low- and short-term response against HA and very low or no anti-NA response, INFLUSOME-VAC produced high titers of both anti-HA and anti-NA antibodies (Abs) in young and old mice that persis ted for at least 6 months. Moreover, the anti-NA Abs efficiently cross-reac ted with several N2 viral subtypes spanning 20 years. and such vaccines aff orded partial protection against heterosubtypic viral infection. (C) 2001 E lsevier Science Ltd. All rights reserved.