Antibody response to one and two doses of influenza virus subunit vaccine.

Antibody studies were undertaken to evaluate the responses after one and two-dose schedules of influenza immunization with subunit influenza vaccine. The responses were studied in two adult population groups after the administration of a vaccine containing the most recent epidemic strains A/Pt Chalmers/73 and B/Hong Kong/8/73. Responses to the A component of the vaccine were greater than those to the B strain. Patients with initially low antibody levels responded better than those with higher levels. There was little additional benefit from the second dose of vaccine.