Immunoprophylaxis to limit a hepatitis B epidemic among women undergoing in vitro fertilization

Women (175) who participated in an in vitro fertilization (IVF) programme were possibly exposed to hepatitis B virus. Later it became evident that 79 women had a hepatitis B infection, 49 were exposed but not infected and 47 were not exposed. Hepatitis B immunoglobulin (HBIg) and recombinant hepatitis B vaccine (HBvaxDNA) were offered to all women and partners except for those with established hepatitis B. Women were given an 'intensive' schedule of HBIg (0, 1 months) and vaccine (0, 1, 2, 6 months). Spouses received HBIg (0, 1 months) and vaccine (0, 1, 6 months). Blood samples were taken at the time of diagnosis of the HBV epidemic and at regular intervals. Hospital personnel immunized according to the regular schedule (0, 1 and 6 months) with HBvaxDNA but without HBIg served as controls. During the observation period of 7 months anti-HBc seroconversion was not observed. At month 7 the seroconversion rate for males was 89%, significantly lower than that for females (100%). Intermediate rates were found for the control groups (94%). Significant differences in geometric mean titre between IVF-treated patients and controls were, however, observed at month 7 (551 mIU ml-1 for female patients versus 1582 mIU ml-1 for their controls and 171 mIU ml-1 for males versus 899 mIU ml-1 for their controls). Possible explanations for the low reactivity to HBsAg vaccine are discussed.