Age-related hepatitis B seroconversion rates in health care workers

Background: Protective hepatitis titers are reported for more than 90% of healthy adults who received three intradeltoid injections of vaccine. Some factors that influence seroconversion rates include age, sex, and presence of chronic diseases. Methods: Because of work-related factors that placed them at risk of acquiring hepatitis B, 112 employees, who ranged in age from 20 to 70 years with a mean age of 39.2 years, completed the hepatitis B vaccination series between 1986 and 1993. All participants received three vaccinations. Results: Hepatitis B surface antibody did not develop in 16 of 112 recipients (14.2%, 95% CI, 7.6% to 20.8%). Race, sex, and duration to antibody titer did not affect rates of seroconversion. Age greater than 50 years was associated with significant decreased seroconversion rates (64.7%, 95% CI, 42.0% to 87.4%) compared with seroconversion rates of those younger than 50 years of age (89.5%, 95% CI 83.3% to 95.7%, p = 0.02). Conclusions: Our results indicate that when a hepatitis B immunization program is implemented, seroconversion rates are lower than published rates for healthy adults and adolescents. We recommend taht seroconversion data from immunization programs for employees at risk for hepatitis B be reviewed and that postimmunization testing be considered to ensure adequate protection for those employees at highest risk for nonconversion.