The serological data on 15- to 19-year-old women in British Columbia 7 years after hepatitis B (HB) vaccination, presented recently by Meenakshi Dawar and associates,1 are intriguing. Even though there were no hepatitis B surface antigen (HBsAg) carriers, 0.6% of the women in this age group had antibodies to HB core antigen. It might be appropriate to investigate all of the serum aliquots for these women, if still available, for a low-level HBsAg carrier state.
These women might have been infected with the HB virus a long time ago, but with no development of antibodies to HBsAg, or antibody levels might subsequently have fallen to undetectable levels. The women might have experienced recent clearance of HBsAg from the blood after a bout of acute hepatitis, or they might have a chronic HBsAg carrier state. Alternatively, they might have had a low-level carrier state with undetectable levels of HBsAg.2 To distinguish these possibilities, it might have been preferable to test them for circulating DNA of the HB virus.
Any low-level carriers could be tested for active viral replication by measuring levels of HB e antigen and HB viral DNA. These tests might assist in selecting those eligible for therapeutic antiviral intervention with interferon and lamivudine.
Subhash C. Arya Research Physician Centre for Logistical Research and Innovation New Delhi, India