Veille documentaire MTPH

Auteur     A. Katoonizadeh
Auteur     M. Sharafkhah
Auteur     M. R. Ostovaneh
Auteur     A. Norouzi
Auteur     N. Khoshbakht
Auteur     A. Mohamadkhani
Auteur     L. Eslami
Auteur     A. Gharravi
Auteur     A. Shayanrad
Auteur     M. Khoshnia
Auteur     S. Esmaili
Auteur     J. George
Auteur     H. Poustchi
Auteur     R. Malekzadeh
Volume     23
Numéro     10
Pages     805-811
Publication     Journal of Viral Hepatitis
ISSN     1365-2893
Date     Oct 2016
Résumé     We evaluated the immune response to neonatal HBV immunization in children of infected parents 10-18 years after primary vaccination. Healthy individuals immunized with an infantile course of three doses of HBV vaccine were tested for persistence of anti-HB surface antibody (HBsAb). Those with an HBsAb level of <10 IU/mL received a booster dose of the vaccine with subsequent doses to those without protective titres. HBsAb concentrations were determined 4 weeks after each dose of the booster vaccine. The data were analysed separately for three age groups: 10-11, 12-14 and 15-18 years old. A total of 541 healthy individuals were studied. The highest seroprotection rate of 48% was observed in the youngest vaccinees (10-11 years old). This declined to 26.5% in the oldest (15-18 years old) group (P = 0.008). The youngest vaccinees showed the highest rate of anamnestic immune responses (96%). However, 25% of oldest individuals failed to mount an anamnestic immune response in challenge with a booster dose of the vaccine (P = 0.005), suggesting waning immunity with increasing age. Age (OR: 0.80; P = 0.01) and prebooster HBsAb levels (OR: 0.37; P = 0.01) identified responders to first booster doses of the vaccine by logistic regression analysis. The majority of high-risk vaccinees showed anamnestic immune response 10-11 years after primary immunization. However, we found a significant proportion (25%) of older individuals with no anamnetic response, which suggests a waning of immune memory. Detailed long-term follow-up studies are necessary to determine the risk of natural infection among these individuals before a booster schedule can be recommended.