Modulation of immune response to rDNA hepatitis B vaccination by psychological stress.

In a previous study it was shown that antibody formation after vaccination with a low-dose recombinant DNA (rDNA) hepatitis B vaccine was negatively influenced by psychological stress. The present study was designed to assess whether the same inverse relation between HBs-antibody levels and psychological stress could be observed, while administering the standard, and thus higher, dose of vaccine. Volunteers (n = 68) scoring extremely low or high on a combination of questionnaires measuring daily problems and psychoneurotic symptoms were selected for participation. Antibody levels were determined 2, 6, and 7 months after the first vaccination. Questionnaires were completed before entering the study and at month 6. In contrast to the previous study, psychological stress was not found to be related to the antibody levels at any timepoint. These results suggest that, under certain conditions, stress-induced immunomodulation in vivo might be dependent on antigen dose.