Recombinant Baculovirus Influenza A Hemagglutinin Vaccines Are Well Tolerated and Immunogenic in Healthy Adults

In a prospective double-blind trial, the reactogenicity and immunogenicity of recombinant baculovirus influenza A vaccines containing purified full-length hemagglutinin (HA) were compared with standard trivalent inactivated vaccine (TIV). The recombinant baculovirus influenza A vaccines (rHA0) were monovalent (containing 45 μg of A/Beijing/92[H3] and 15, 45, and 135 μg of A/Texas/91[H1]) and bivalent (containing 45 μg of both A/Beijing/92 and A/Texas/91). The bivalent rHA0 vaccine produced fewer local side effects than the TIV (50% vs. 88%, P =.003). The hemagglutinin inhibition (HAI) responses (defined as a ≥4 increase in HAI) to A/Beijing rHA0 in the monovalent A/Beijing/92, the bivalent vaccine, and the TIV were 68%, 76%, and 46%, respectively (P =.086). Increasing doses of A/Texas rHA0 (15 μg [60%], 45 μg [69%], and 135 μg [76%]) and bivalent HA (76%) gave better immunologic responses to H1 than did TIV (31% ; P =.003).