Osteopathic manipulative treatment (OMT) facilitates the movement of lymphatic fluid and may enhance the immunologic response to infection or injected antigen. In this investigation, two groups of volunteers were vaccinated with recombinant hepatitis B vaccine, given at 0, 5, and 25 weeks. The experimental group (n = 20) received OMT (lymphatic and splenic pump) three times per week for 2 weeks after each vaccination. Control subjects (n = 19) received vaccine but no OMT. Resultant serum antibody levels were measured by enzyme immunoassay. Fifty percent of subjects in the treatment group achieved protective antibody titers (> or = 10 mIU/mL) on the 13th week with an average titer of 374 mIU/mL. Only 16% of the control subjects had positive antibody responses, with average titers of 96 mIU/mL. At all time points from week 6 on, the average anti-hepatitis B titer was higher in the treatment group than in the control group. These data suggest an enhanced immunologic response in subjects who received OMT.