Persistence of antibody to hepatitis B and protection from disease among Alaska natives immunized at birth.
BACKGROUND
Alaska Native (AN) children were at high risk of acquiring hepatitis B virus (HBV) infection before vaccination began in 1983. We evaluated the long-term protection from hepatitis B (HB) vaccination among AN children immunized when infants.


METHODS
During 1984-1995, we recruited a convenience sample of AN children who had received a three dose series of HB vaccine starting at birth and had serum antibody to hepatitis B (anti-HBs) concentrations of >/= 10 mIU/mL at 7-26 months of age. We evaluated anti-HBs concentrations and the presence of anti-HBc in participants' sera every other year up to age 16 years. Anti-HB core antigen (anti-HBc)-positive specimens were tested for hepatitis B surface antigen and for HBV DNA.


RESULTS
We followed 334 children for 3151 person-years (median, 10 years per child) with 1610 specimens collected. Anti-HBs concentrations dropped rapidly among all participants. Among children 2, 5 and 10 years of age, 37 of 79 (47%), 33 of 176 (19%) and 8 of 95 (8%), respectively, had anti-HBs concentrations of >/= 10 mIU/mL. Receipt of recombinant vaccine was significantly associated with a more rapid antibody decline (P < 0.001). Six (1.8%) children acquired anti-HBc, 3 of whom had definite breakthrough infections (at least 2 consecutive anti-HBc-positive specimens or at least 1 anti-HBc-positive specimen and HBV DNA detection by PCR). None of these children had detectable hepatitis B surface antigen, and none had symptoms of hepatitis.


CONCLUSIONS
Anti-HBs concentrations declined over time among AN infants successfully immunized with HB vaccine starting at birth. Transient anti-HBc appeared in a small percentage of children; however, none developed clinical signs of hepatitis or chronic HBV infection.
Dentinger
Catherine M
CM
Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
McMahon
Brian J
BJ
Butler
Jay C
JC
Dunaway
Charlotte E
CE
Zanis
Carolyn L
CL
Bulkow
Lisa R
LR
Bruden
Dana L
DL
Nainan
Omana V
OV
Khristova
Marina L
ML
Hennessy
Thomas W
TW
Parkinson
Alan J
AJ
D000367:Age Factors; D000413:Alaska / Q000453:epidemiology; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006509:Hepatitis B / Q000208:ethnology* / Q000276:immunology / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006801:Humans; D007109:Immunity / Q000502:physiology; D007115:Immunization Schedule; D007223:Infant; D007231:Infant, Newborn; D004930:Inuit / Q000706:statistics & numerical data; D008297:Male; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment
D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines