Hepatitis B virus vaccine: early and late response in Chileans with high risk of infection Vacuna contra el virus de la hepatitis B: respuesta precoz y tardía en Chilenos con alto riesgo de infección.

Abstract

BACKGROUND: Hepatitis B vaccine has demonstrated to be very effective and safe preventing hepatitis B virus infection. Long term protection induced by hepatitis B vaccination depends on the initial immune response and the declining rate of anti-HBs titers. AIM. To investigate early and late response to hepatitis B vaccine in a sample of high risk Chilean population. MATERIAL AND METHODS: Thirty one subjects (20 relatives of hepatitis B chronic carriers, 10 health service workers and one HIV seropositive) were vaccinated with a plasma derivated hepatitis B vaccine. Early and late response were estimated by anti-HBs titers. RESULTS: Twenty eight subjects (90%) produced protective titers of anti-HBs after 2 months from the third dose of vaccine (early response), and they remained at these levels in 75% of vaccinated individuals after three years (late response). All the subjects without protective titers after the three year follow up had produced anti-HBs levels lower than 300 UI at the