Obesity as a predictor of poor antibody response to hepatitis B plasma vaccine.

Factors associated with lack of antibody response to the hepatitis B virus plasma vaccine were retrospectively evaluated by means of a logistic regression in 194 previously seronegative staff members of a community hospital. All subjects had received three doses of vaccine by intramuscular buttock injection using a 1-in, 23-gauge needle. Overall, only 55.7% of subjects developed detectable antibody to hepatitis B surface antigen in serum after immunization. The weight-height index served as a surrogate measure of obesity. Predictors of poor immunogenic response to hepatitis B vaccine included higher weight-height index, older age, and vaccine batch. Sex, race, timing of vaccine doses, and timing of postimmunization determination of antibody to hepatitis B surface antigen were not predictors of vaccine efficacy.