Immunologic evaluation of hepatitis B vaccine application in hospital staff

The aim of our study was to assess immunological changes in hospital employees vaccinated five years ago with a recombinant hepatitis B vaccine.

148 hospital employees were examined at different time periods during 5 years following a three-dose schedule of intramuscular immunization with a recombinant DNA hepatitis B vaccine (Engerix-B).

At the end of a 5-year period, 20 vaccinees (13.5%) demonstrated a low level of HBs antibodies, namely < 10 mIU/ml being evaluated as lack of protection, 46 (31.1%) showed titers between 11 and 100 mIU/ ml corresponding to feeble protection, 54 (36.5%) were with titers > 100 mIU/ml considered as sufficiently protected and, surprisingly, in 28 vaccinated persons (18.9%), titers of HBs Ab were over 1000 mIU/ml corresponding to high protection. The HBsAg were never detected among the entire vaccinated group. Averaged amounts of serum immunoglobulins (IgG, IgM, IgA) were lower relatively to normal values only among unprotected or feebly protected vaccinees.

Our data demonstrate that postvaccinal titers are in linear dependence on the time elapsed since the vaccination and also evidence that some other immunological factors influence the outcome of vaccination.