Five adjuvants were tested for their effect on the immune response in guinea pigs to the hemagglutinin antigen of influenza virus strain B/Panama. Vaccines containing 924 micrograms of hemagglutinin antigen/ml were prepared at high and low doses of Freund's complete and incomplete adjuvants, Syntex adjuvant, RIBI's adjuvant, TiterMax adjuvant, and aluminum phosphate adjuvant. Responses to these vaccines were compared with those to a control vaccine containing influenza virus B/Panama hemagglutinin antigen and saline. On day 28, vaccines containing the following adjuvant doses had significantly higher titers than the titer for the control: Freund adjuvants at high and low doses, RIBI at high dose, TiterMax at high and low doses, and aluminum phosphate at high dose. On day 42, vaccines containing the following adjuvant doses had significantly higher titers than that for the control: Freund adjuvants at high and low doses, RIBI at high dose, TiterMax at high dose, and aluminum phosphate at high dose. Freund adjuvants at high and low doses, RIBI adjuvant at high dose, and aluminum phosphate at high dose caused significantly greater swelling at the inoculation site than did the control vaccine. TiterMax adjuvant at high and low doses, and aluminum phosphate at low dose caused minor swelling at the inoculation site, but it was not significantly different from the swelling caused by the control vaccine. Syntex adjuvant at high and low doses, RIBI at low dose, and control (saline/antigen) at high and low doses caused no swelling after inoculation. Overall, the high dose of adjuvants caused greater tissue swelling than did the low dose of adjuvants.(ABSTRACT TRUNCATED AT 250 WORDS)