Immunisation of infants at risk of perinatal transmission of hepatitis B: retrospective audit of vaccine uptake.

Perinatal transmission of hepatitis B virus is the infection of infants at birth by mothers who are positive for hepatitis B surface antigen. Around 85% of babies born to mothers who are also positive for hepatitis B e antigen become infected. Immunoprophylaxis initiated shortly after birth— that is, after exposure to the virus—can prevent perinatal transmission. Passive prophylaxis with hepatitis B immunoglobulin is 50-90% efficacious, active prophylaxis with hepatitis B vaccine is 75-90% efficacious, and combined active and passive prophylaxis is > 90% efficacious. Antenatal screening for hepatitis B surface antigen is universal in the West Midlands. The vaccination schedule for all babies of mothers with hepatitis B virus is 0 (within 48 hours of birth), 1, 2, and 12 months. Babies of mothers positive for hepatitis B e antigen are given 200 IU of hepatitis B immunoglobulin at birth as additional protection. Blood samples are taken at 12 months to monitor the effectiveness of vaccination, to audit uptake, and to identify children who have become carriers. We carried out a retrospective audit on the six maternity units serving Birmingham to establish vaccine uptake and identify problems associated with compliance.