Antibody response of young adults to experimental influenza A/New Jersey/76 virus vaccines

In military personnel aged 17-25 years, only one of four experimental influenza A/New Jersey/76 virus vaccines produced a satisfactory hemagglutination-inhibiting (HAI) antibody response when a dose of 200 chick cell-agglutinating (CCA) units was used. A second injection of 400 CCA units of vaccine caused seroconversion in all persons. Although an early comparison of experimental split-product and whole-virus vaccines suggested that the former were relatively ineffective, a later comparison with different lots of the vaccines showed no difference between vaccines of these two types. The influenza A/NJ/76 virus vaccine evoked a high HAI antibody response to influenza A/PR/8/34 (H0N1) virus but not to H1N1 or H3N2 strains.