[Immunity against tetanus in childhood].

In order to evaluate the programs of vaccination against tetanus, we have studied the presence of specific antibodies in a sample of children and adolescents from our region. We used a passive hemagglutination test, corroborating the results by a biological assay based on toxin-neutralization. Among the subjects investigated, 93.2% (551/591) had neutralizing toxin-antibodies at a protective level (> or = 0.01 ui/ml). The younger children were more protected (97.5% in children from 1 to 5 years old, and 79.2% in children from 16 to 19 years of age), (X2 = 25.39, p = 0.000-). We did not find any significant differences between the sexes in the degree of protection. Among protected subjects, the higher antibody titers were observed in children from 6 to 10 years old, coinciding with the age of a booster vaccine. The results show an excellent immunization coverage among the childhood population in our region. They also confirm the high effectiveness of this vaccine. However, this high protection was not found among people above the adolescent period.