Evaluation of a recombinant hemagglutinin expressed in insect cells as an influenza vaccine in young and elderly adults

Healthy subjects <45 years old (young adults) or >65 (elderly adults) were randomized in double-blind fashion to receive intramuscularly subvirion trivalent influenza vaccine, placebo, or 15, 45, or 135 mu g of the hemagglutinin (HA) of the influenza A/Beijing/32/92 (H3N2) virus expressed in insect cells by a recombinant baculovirus (rHA0). All vaccines were well tolerated, Both young and elderly adults manifested serum hemagglutination-inhibition, virus neutralizing, and HA-specific Ige ELISA antibody responses to rHA0 vaccine, In young adults given 135 mu g of rHA0, the vaccine was significantly more immunogenic than subvirion influenza vaccine, Elderly adults also had increased antibody responses to 135 mu g of rHA0 compared with subvirion vaccine, but the difference was not statistically significant, These results demonstrate that high-dose rHA0 vaccines are well tolerated and effectively induce both functional and binding serum HA-specific antibody in young and elderly adults.