Dose-related safety and immunogenicity of a trivalent baculovirus-expressed influenza-virus hemagglutinin vaccine in elderly adults

Background. Influenza-virus hemagglutinin ( HA) protein expressed in insect cells by recombinant baculovirus is a candidate influenza vaccine. Methods. In a randomized, double-blind trial conducted in 399 adults >= 65 years of age, the efficacy of trivalent inactivated influenza vaccine (TIV) licensed for intramuscular injection was compared with that of trivalent baculovirus-expressed HA vaccine administered at doses of 15 mu g, 45 mu g, or 135 mu g of each HA. Results. Compared with TIV, baculovirus-expressed HA vaccine was safe and induced better serum antibody responses to the H3 component when administered at doses of 45 mu g or 135 mu g of each HA. Conclusions. Baculovirus-expressed HA is a safe and immunogenic influenza vaccine in elderly adults.