Usefulness of influenza vaccination in the elderly.

Since influenza morbidity and mortality are high in the elderly, the usefulness of vaccination has been evaluated. One hundred and twenty-six older persons aged 60-90 yr were given a vaccine consisting of the 3 antigens Singapore, Shanghaï and Yamagata, the latter 2 being new antigens. Antibody levels for each of the antigens were determined by ELISA calibrated in HA units prior to and 1 month after vaccination. Before vaccination, antibodies to Shanghaï and Singapore antigens were found in practically all sera tested, and antibodies to Yamagata antigen in only 66% of sera. After vaccination, significant levels of antibodies to all 3 antigens were found in sera tested. Thus, it was observed that influenza vaccination proved to be effective in the elderly. The elderly should be immunized against influenza, since this is a safe and efficacious preventive measure. In addition, vaccination should limit the spreading of influenza in nursing homes.