Prevention and Control of Influenza by Chemoprophylaxis and Chemotherapy

Abstract
CHEMOTHERAPEUTIC drugs to prevent and treat influenza would be of only academic interest if safe vaccines were always available, produced lasting or reasonably persistent immunity, and were used effectively. At present, neither the goals nor extent of use of immunoprophylaxis for influenza is adequate to produce any "herd immunity" or substantially interrupt virus transmission. Available vaccines induce a rise in serum antibody in approximately 85% of vaccinees, but produce respiratory secretory antibody in only a small percentage. Protection against influenza in the same year occurs in about 70% of vaccinees. When a major new antigenic strain of influenza virus appears, less vaccine is available, two or more injections may be required, and the production of immunity is less. The duration of immunity following killed-virus vaccines is limited to a few years, and there is uneasiness among biologists about the advisability of using defective live virus preparations that might produce latent