Duration of protection after infant hepatitis B vaccination series.
BACKGROUND
Little is known about duration of protection after the infant primary series of hepatitis B (HB) vaccine in settings of low HB endemicity. This study sought to determine the proportion of adolescents immunized as infants who had protective titers of antibody to hepatitis B surface antigen (anti-HBs) before and after a challenge dose of vaccine.


METHODS
US-born 16- through 19-year-olds who received a recombinant HB vaccine 3-dose series initiated within 7 days of birth (group 1) or at ≥4 weeks of age (group 2) and completed by 12 months of age were enrolled. Participants had serologic testing before and 2 weeks after randomization to receive a challenge dose of 10 µg or 20 µg of Engerix-B. Baseline and postchallenge levels of anti-HBs were compared by group, challenge dosage, and demographic and behavioral characteristics.


RESULTS
At baseline, 24% had protective anti-HBs levels of ≥10 IU/mL; 92% achieved protective levels after challenge dose. Although group 1 had a lower proportion of seroprotection at baseline, group and challenge dosage were not associated with postchallenge proportion of seroprotection. Being in group 2, higher test dosage, higher baseline geometric mean titer, and nonwhite race were associated with significantly higher geometric mean titer after challenge dose.


CONCLUSIONS
More than 90% of study participants immunized against HB as infants exhibited a seroprotective response to a challenge dose of vaccine. Duration of protection from the primary infant HB vaccine series extended through the adolescent years in the setting of low HB endemicity.
Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; amym@ouhsc.edu.
Amy B
AB
Middleman
Department of Pediatrics, Baylor College of Medicine, Houston, Texas; and.
Carol J
CJ
Baker
Department of Pediatrics, Baylor College of Medicine, Houston, Texas; and.
Claudia A
CA
Kozinetz
Centers for Disease Control and Prevention, Atlanta, Georgia.
Saleem
S
Kamili
Department of Pediatrics, Baylor College of Medicine, Houston, Texas; and.
Chi
C
Nguyen
Centers for Disease Control and Prevention, Atlanta, Georgia.
Dale J
DJ
Hu
Centers for Disease Control and Prevention, Atlanta, Georgia.
Philip R
PR
Spradling
D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D019353:Endemic Diseases / Q000517:prevention & control*; D005260:Female; D006509:Hepatitis B / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013781:Texas
C075654:Engerix-B; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines
adolescent immunization; hepatitis B; hepatitis B vaccine; infant immunization