Immunological potency of a subunit influenza vaccine in adults.

The immunological potency of a subunit influenza vaccine (from A/England/42/72 virus) and of two commercial whole-virus vaccines (containing either A/England/42/72 or A/Hong Kong/68 virus) was studied in adults in an industrial plant. Serum samples were taken in vaccinated and control non-vaccinated subjects prior to and three weeks and five months after the vaccination. Most of the vaccinees developed high levels of hamagglutination inhibiting antibodies against all the type A influenza viruses employed in the test; these antigens included a new strain (A/Dunedin/73) that had not previously circulated in Czechoslovakia. The antibody response after the subunit vaccine was somewhat better than after the whole-virus vaccines administration. The whole-virus vaccine from the A/England/42/72 virus was more efficient in inducing antibody response against the more recent isolates than the A/Hong Kong/68 virus vaccine.