[Hepatitis B vaccination in children and adolescents]

This study's main aim was to investigate the immunogenicity of genetic recombinant vaccine in children and adolescents in Madrid, with the intention of determining the length of protection according to the titer of antibodies. A second aim was that of finding the optimum vaccine dosage, in order to suggest possible courses of action leading to an adequate strategy of vaccination.

Crossover study.

Three educational centres in Madrid.

1,184 pupils between 5 and 17 years old.

Each individual was given three doses of Engerix B recombinant vaccine in the deltoid area at 0, 1 and 6 months. The vaccine dosage was 10 micrograms for children under 12 and 20 micrograms for those aged 12 and over.

The pre-vaccination markers were determined. A month after completing the vaccination, the titer of antibodies was quantified using the Abbott laboratories' microenzyme-immunoanalysis technique. The overall seroprotection rate was 98.9%. The MGT of the titer of antibodies was 9,283.2 mUI/ml. The seroprotection rates were similar among children under 12. The rates were also similar among those who were 12 or over, with titers of antibodies showing significantly higher in the children aged 12 or over.

Given the good results obtained, we consider that the children will be protected for about 10 years. We suggest that all children and/or adolescents should be vaccinated as a means of controlling Hepatitis B. The recommended dosage for children under 8 is 10 micrograms and for those aged 8 and over, 20 micrograms.