BACKGROUND: In 2000, hexavac and infanrix hexa were licensed in Europe for primary immunisation of children against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, and invasive infections caused by Haemophilus influenzae b. In 2005, hexavac was suspended because of concerns about the long-term immunogenicity of its hepatitis B component. We aimed to assess the duration of immunity and need for booster injections in children primed with these vaccines. METHODS: In an open-label, randomised, controlled, multicentre study in six local health units and at the Bambino Gesù Paediatric Research Hospital in Italy, antibody concentrations were measured 5 years after immunisation of infants with hexavac or infanrix hexa. Children with concentrations of antibodies to hepatitis B surface antigen (anti-HBs) lower than 10 mIU/mL were randomly assigned by simple randomisation to receive a booster of HBVaxPro or engerix B monovalent hepatitis B vaccine and tested 2 weeks later. Primary endpoints were the proportion of children with anti-HBs concentrations of at least 10 mIU/mL, geometric mean concentrations (GMCs) of antibody 5 years after vaccination, and the proportion of children with anti-HBs concentrations lower than 10 mIU/mL who had anamnestic response to booster. The study is registered with Agenzia Italiana del Farmaco, code FARM67NFPN. FINDINGS: 1543 children were enrolled, 833 had received hexavac and 710 infanrix hexa. 831 children who received hexavac and 709 who received infanrix hexa were included in the analysis. 319 children who received hexavac (38.4%, 95% CI 35.1-41.7) had anti-HBs concentrations of at least 10 mIU/mL compared with 590 who received infanrix hexa (83.2%, 80.5-86.0; p<0.0001). GMCs before booster were 4.5 mIU/mL in the hexavac group compared with 61.3 mIU/mL in the infanrix hexa group (p<0.0001). After booster 409 (92.1%, 89.6-94.6) of 444 children primed with hexavac and 99 (94.3%, 89.8-98.7) of 105 primed with infanrix hexa had anti-HBs concentrations of at least 10 mIU/mL (p=0.4); GMCs were 448.7 mIU/mL and 484.9 mIU/mL (p=0·6). The two booster vaccine groups did not differ in number of side-effects; no serious adverse events were reported. INTERPRETATION: 5 years after immunisation with hexavalent vaccines, immunological memory seems to persist in children with anti-HBs concentrations lower than 10 mIU/mL, suggesting that booster doses are not needed. Additional follow-up is needed.
Hepatitis B immune memory in children primed with hexavalent vaccines and given monovalent booster vaccines: an open-label, randomised, controlled, multicentre study / A.R. Zanetti, L. Romano’, C. Giambi, A. Pavan, V. Carnelli, G. Baitelli, G. Malchiodi, E. Valerio, A. Barale, A.M. Marchisio, D. Montu’, A.E. Tozzi, F. D’Ancona, Study Group. - In: THE LANCET INFECTIOUS DISEASES. - ISSN 1473-3099. - 10:11(2010), pp. 755-761.
|Titolo:||Hepatitis B immune memory in children primed with hexavalent vaccines and given monovalent booster vaccines: an open-label, randomised, controlled, multicentre study|
ZANETTI, ALESSANDRO REMO (Primo)
ROMANO', LUISA (Secondo)
|Parole Chiave:||Child ; Child, Preschool ; Diphtheria-Tetanus-Pertussis Vaccine ; Diphtheria-Tetanus-acellular Pertussis Vaccines ; Female ; Hepatitis B ; Hepatitis B Antibodies ; Hepatitis B Surface Antigens ; Hepatitis B Vaccines ; Humans ; Immunization, Secondary ; Immunologic Memory ; Italy ; Male ; Poliovirus Vaccine, Inactivated ; Vaccines, Combined|
|Settore Scientifico Disciplinare:||Settore MED/42 - Igiene Generale e Applicata|
|Data di pubblicazione:||2010|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/S1473-3099(10)70195-X|
|Appare nelle tipologie:||01 - Articolo su periodico|