[Predicted duration of protective anti-HBs antigens in Peruvian health care workers after six years of vaccination].

Given the importance attributed to the protection of health care workers against viral Hepatitis B (VHB) by the World Health Organization (WHO) and the Center for Disease Control (CDC), in 1993, the Instituto Peruano del Seguro Social (Social Security Peruvian Institute), today known as ESSALUD, ruled the vaccination of personnel in risk working in the 4 national hospitals, using Cuban vaccine Heberbiovac HB (20mg, schedule 0, 1, 2 months). Our purpose was to evaluate the antibody persistence in the vaccinated individuals after six years from immunization, and the possible presence of HB virus infection markers. Sera from 144 health care workers were studied, for a 70.24% coverage, in relation to the initially seroprotected in the 1993 study. For markers detection, commercial immunoenzymatic methods were used. HBsAg and anti-HBc were negative in all the serology samples studied, thus we conclude that no evidence of infection by this virus was found in any of the vaccinated subjects. AntiHBs was positive, being all of them seroconverted, with seroprotection and hyperresponse as of 91.6% and 43.7% respectively. The mean life time of antiHBs (t 1/2) is three years,predicting that the antibodies level will be over 10 IU/l until after 15 years from the end of the schedule. The subjects under 40 had significantly higher levels of seroprotection and hyperresponse, being the females those that stayed in the upper categories of response. Evaluation of the post-reinforcement memory in the seroconverted, not protected cases, is recommended, as well as extend the work with ESSALUD to other hospitals in the country.