Comparative immunogenicity under held conditions of two recombinant hepatitis B vaccines in 8-10-year-old children

The immunogenicity of two hepatitis B vaccines was compared in 8-10-year-old children immunized in a school program. One year apart, 1129 children received Engerix-B 10 mu g vaccine (EB), and 1126 received Recombivax-HB 2.5 mu g (RB), following the 0, 1, 6 schedule. Blood samples were collected one month after the third dose. Anti-Hbs were measured by commercial radioimmunoassay, In the EB group, 99.1% of the children seroconverted (greater than or equal to 2 IU/l) compared to 99.7% in the RHB group (p = 0.09). The seroprotection rate (greater than or equal to 10 IU/l) was similar for both groups: 98.9% in the EB group and 99.2% in the RE group (p = 0.66). However, GMCs of anti-HBs were higher in children given EB compared to those given RE (7307 vs. 3800 mIU/ml, p < 0.0001). This study showed that both vaccines were highly immunogenic, in the course of a regular field immunization program. However, the difference observed in the antibody levels attained according to the vaccine may play a role in the longterm protection of these children. (C) 2000 Elsevier Science Ltd, All rights reserved.