VIRUS-LIKE PARTICLES AS A ROTAVIRUS SUBUNIT VACCINE

Rotavirus subunit vaccines are being evaluated for use in humans. The virus-like particles (VLPs) for these vaccines are produced in insect cells coinfected with combinations of baculovirus recombinants express ing bovine RF VP2 and simian SA11 VP4, VP6, or VP7 rotavirus proteins. VLPs were administered parenterally to mice and rabbits, and the immu nogenicity and protective efficacy of the vaccines were evaluated. Rab bits vaccinated with VP2/4/6/7 or VP2/6/7 VLP combinations developed h igh levels of rotavirus-specific serum antibody and fecal IgG but not fecal IgA. The induction of fecal IgG was associated with total or par tial protection from oral challenge with ALA rotavirus. Heterotypic se rum and fecal neutralizing antibody was induced in mice vaccinated par enterally with G1 VP2/6/7 or VP2/4/6/7 VLPs. VLPs were highly immunoge nic when administered in QS21 adjuvant, inducing serum neutralizing an tibody titers comparable to those induced by SA11 virus. VLPs are effe ctive immunogens when administered parenterally and may be an effectiv e subunit vaccine.