Efficacy of hepatitis B virus (HBV) vaccine in long term prevention of HBV infection.
Efficacy of HBV vaccine in long term prevention of HBV infection was evaluated at 3 years after vaccination in 38 children and 61 adults. All vaccinees were negative for all HBV markers (HBsAg, anti-HBs and anti-HBc) before vaccination. Vaccines (Hevac B) were given for 3 doses, one month apart, to 38 children aged 1 month - 14 years and 61 adults aged 15-45 years. After 3 years of vaccination, blood specimens were collected for the determination of HBsAg, anti-HBs and anti-HBc. The results revealed that no HBsAg antigenemia was found in all 99 vaccinees. Anti-HBs could not be detected in 4 children and 11 adults and this occurred only in the group of subjects who had initial anti-HBs less than 100 mlU/ml at 2 months after the last dose of vaccination. At three years after the first course of vaccination, 89.4 percent of children and 83.4 percent of adults still have anti-HBs above protective level (more than 10 mlU/ml) with geometric mean titers of 101 and 35 mlU/ml in children and in adult groups, respectively. The anti-HBc was detected in 2 out of 38 children and 10 out of 61 adults, but none of them became chronic hepatitis B carriers or developed clinical disease. It is recommended that everyone with anti-HBs values below 100 mlU/ml two months after the last dose of vaccine should be revaccinated with a booster dose within 6 months. Those with anti-HBs levels higher than 100 mlU/ml, should be checked up at 3 years; if the anti-HBs is less than 10 mlU/ml, they should be revaccinated.
Pongpipat
D
D
Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand.
Suvatte
V
V
Assatteerawats
A
A
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008875:Middle Aged; D013997:Time Factors; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000627:therapeutic use*
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D014761:Viral Hepatitis Vaccines