Augmentation of hemagglutination-inhibition (HI) antibodies in gilts of breeding age by large dosages of human A/New Jersey/76 influenza vaccine.

Fifteen gilts of breeding age were studied. Four received three 4 ml. doses three weeks apart of an experimental killed swine influenza vaccine containing A/Swine/ill/65 antigen, four received three ml. doses three weeks apart of a human influenza vaccine containing A/New Jersey/76 antigen and three received two doses of human influenza vaccine followed by a 3 ml. third dose of experimental swine influenza vaccine. All except one vaccinate responded to two doses of vaccine by the time of the third dose of vaccine. HI titers were highest four weeks after the third dose of vaccine. Geometric mean titers were highest in animals receiving human influenza vaccine containing A/New Jersey/76. Titer profiles dropped markedly by 60 days after the third vaccination.