title: Persistence of hepatitis A vaccine induced seropositivity in infants and young children by maternal antibody status: 10-year follow-up.
abstract: Persistence of seropositivity conferred by hepatitis A vaccine administered to children <2 years of age is unknown and passively transferred maternal antibodies to hepatitis A virus (maternal anti-HAV) may lower the infant's immune response to the vaccine. One hundred ninety-seven infants and young children were randomized into three groups to receive a two-dose hepatitis A vaccine: group 1 at 6 and 12 months, group 2 at 12 and 18 months, and group 3 at 15 and 21 months of age. Within each group, infants were randomized by maternal anti-HAV status. Anti-HAV levels were measured at 1 and 6 months and at 3, 5, 7, and 10 years after the second dose of hepatitis A vaccination. Children in all groups had evidence of seroprotection (>10 mIU/mL) at 1 month after the second dose. At 10 years, all children retained seroprotective anti-HAV levels except for only 7% and 11% of children in group 1 born to anti-HAV-negative and anti-HAV-positive mothers, respectively, and 4% of group 3 children born to anti-HAV-negative mothers. At 10 years, children born to anti-HAV-negative mothers in group 3 had the highest geometric mean concentration (GMC) (97 mIU/mL; 95% confidence interval, 71-133 mIU/mL) and children born to anti-HAV-positive mothers in group 1 had the lowest GMC (29 mIU/mL; 95% confidence interval, 20-40 mIU/mL). Anti-HAV levels through 10 years of age correlated with initial peak anti-HAV levels (tested at 1 month after the second dose).
  
  
  CONCLUSIONS
  The seropositivity induced by hepatitis A vaccine given to children <2 years of age persists for at least 10 years regardless of presence of maternal anti-HAV.
authors.affiliation: Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Umid M
authors.initials: UM
authors.lastname: Sharapov
authors.forename: Lisa R
authors.initials: LR
authors.lastname: Bulkow
authors.forename: Susan E
authors.initials: SE
authors.lastname: Negus
authors.forename: Philip R
authors.initials: PR
authors.lastname: Spradling
authors.forename: Chriss
authors.initials: C
authors.lastname: Homan
authors.forename: Jan
authors.initials: J
authors.lastname: Drobeniuc
authors.forename: Michael
authors.initials: M
authors.lastname: Bruce
authors.forename: Saleem
authors.initials: S
authors.lastname: Kamili
authors.forename: Dale J
authors.initials: DJ
authors.lastname: Hu
authors.forename: Brian J
authors.initials: BJ
authors.lastname: McMahon
mesh_terms: D000328:Adult; D000413:Alaska / Q000453:epidemiology; D002675:Child, Preschool; D015331:Cohort Studies; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000208:ethnology / Q000276:immunology / Q000517:prevention & control*; D035922:Hepatitis A Antibodies / Q000097:blood*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data; D007223:Infant; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D008297:Male; D008431:Maternal-Fetal Exchange / Q000276:immunology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology*; D012307:Risk Factors; D013997:Time Factors
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines