Impact of hepatitis B vaccination in children born to HBsAg-positive mothers: a 20-year retrospective study.
BACKGROUND
Preventive measures remain the best approach to control the spread of hepatitis B virus (HBV) infection.


METHODS
To evaluate the effectiveness of vaccination against HBV, we conducted a 20-year retrospective study on 100 subjects, born to hepatitis B surface antigen (HBsAg)-positive mothers, who had received postexposure prophylaxis at the Clinic of Infectious Diseases (Siena University, Italy) during 1984-2004. All patients were tested for the presence of HBsAg, anti-HBs and anti-HB core antigen (anti-HBc).


RESULTS
Two subjects (2%) acquired the infection as shown by the presence of anti-HBc. Of the 98 patients who did not acquire the infection, 62 of these (63.3%) had an anti-HBs concentration considered protective (> or =10 mIU/ml). The percentage of protected subjects decreased in relation to time from vaccination with a significant reduction (p = 0.009) of anti-HBs geometric mean titre (GMT) after 5 years, which reached the level of 10 mIU/ml after about 15 years. No patients without protective concentration have acquired the infection as of today. Only 12% of the HBsAg-positive mothers were followed in specialized structures after pregnancy, reflecting the scarce knowledge of the problem in the general population.


CONCLUSIONS
Our data, while confirming the effectiveness of anti hepatitis B vaccination, highlight the need for postvaccination follow-up, particularly in high-risk categories, to prolong protection, through booster doses if necessary. We show, moreover, the importance of maintaining active surveillance in the territory to improve follow-up to chronic carriers and to sensitize families.
Bracciale
L
L
Department of Molecular Biology, Infectious Diseases Clinic, Siena University, Siena, Italy.
Fabbiani
M
M
Sansoni
A
A
Luzzi
L
L
Bernini
L
L
Zanelli
G
G
D000293:Adolescent; D002648:Child; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D007558:Italy; D008297:Male; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D012189:Retrospective Studies; D055815:Young Adult
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines