Immunogenicity of an inactivated hepatitis A pediatric vaccine: three-year post-booster follow-up.
The persistence of anti-hepatitis A virus antibody concentrations was followed over 3 years in 177 healthy children following primary and booster vaccination with an inactivated hepatitis A vaccine, Avaxim 80 pediatric. Seroconversion rates (post-immunization anti-HAV antibody concentration >or=20 mIU/mL) and geometric mean concentrations (GMC) were estimated for each of three age groups: 18 month--3 years, 4--8 years, and 9--15 years. Only subjects who were initially HAV-seronegative at inclusion (<20 mIU/mL) were analyzed. Follow-up visits at years 1, 2, and 3 involved 177, 149, and 135 children, respectively. A decline in GMCs of about 74% occurred during the first year, from 3,060 to 814 mIU/mL overall, but did not continue during years 2 and 3. All subjects remained seropositive (antibody concentration >or=20 mIU/mL), with overall GMCs of 814, 891, and 924 mIU/mL in years 1--3, respectively. The inactivated hepatitis A study-vaccine resulted in sustained seroprotective antibody concentrations in 100% of these children, without a significant decline in antibiotic concentrations over the 3 years following booster injection, thus demonstrating the long-term protection expected with this vaccine.
Dagan
Ron
R
Pediatric Infectious Disease Unit, Soroka University Medical Center, POB 151, Beer-Sheva 84101, Israel. rdagan@bgu.ac.il
Greenberg
David
D
Weber
Françoise
F
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines / Q000009:adverse effects / Q000276:immunology*; D017957:Hepatitis A Virus, Human / Q000276:immunology*; D006801:Humans; D017589:Immunization Programs; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007223:Infant; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000276:immunology*
D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D015164:Vaccines, Inactivated; D014761:Viral Hepatitis Vaccines