[Persistence of antibodies against hepatitis B surface antigens after vaccination against hepatitis B].

In 195 patients vaccinated against hepatitis B the course of anti-HBs concentration was followed over 4 years. Persistence of anti-HBs proved to be dependent on the level of anti-HBs concentration after basal immunization: in 14 subjects with a maximal anti-HBs level between 10 and 100 IU/l the level had dropped to less than 10 IU/l (considered to be the lowest prophylactic concentration), while 7 were anti-HBs negative. Of those who had 101-1000 IU/l after initial immunization 49% had anti-HBs levels under 10 IU/l after 4 years, while 18% were negative. Among subjects with concentrations 1001-10 000 IU/l after the third immunization only 7% had values below 10 IU/l after 4 years, 4.2% were negative. All those who, after the third immunization, had had anti-HBs levels above 10 000 IU/l, 4 years later still had anti-HBs levels of more than 100 IU/l (mean 581 IU/l). Quantitative anti-HBs determination after triple vaccination against hepatitis B thus makes it possible to predict the duration of protection and to determine the timing of re-vaccination.