SEROCONVERSION FAILURE AFTER HEPATITIS-B VACCINATION - EFFECT OF ADDITIONAL VACCINATIONS

One to three repeat vaccinations were undertaken in 63 persons (32 males, 31 females; mean age 29 [17-59] years) who had not or inadequately responded to basal immunization with hepatitis B vaccine (47 non- and 16 hyporesponders). After re-vaccination, 12 of the 47 nonresponders and 11 of 16 hyporesponders formed specific antibodies against hepatitis B surface antigen, anti-HBs, at concentrations above 10 IU/l. Six of 14 persons who had not responded to the first repeat vaccination reached anti-HBs concentrations above 10 U/l after a further injection. Vaccination response was age-dependent. The median age of those subjects who responded to the first re-vaccination was 27 (19-45) years, while the nonresponders' median age was 34 (22-59) years (P < 0.05). Re-vaccination also raised initially low anti-HBs values. These results indicate that some of the nonresponders can obtain reliable protection by revaccination(s).