RESPONSE TO TETANUS TOXOID PRIMARY IMMUNIZATION IN CHILDREN BORN TO HIV-SEROPOSITIVE MOTHERS

Pre- and postvaccination antitetanus (AT) antibody values were investigated in children born to human immunodeficiency virus type 1 (HIV-1)-infected mothers. Twenty-four uninfected and 14 infected children were enrolled in the study as judged by the Centers for Disease Control and Prevention (CDC) classification system and viral isolation or PCR assays. AT antibody values were determined in sera by hemagglutination assay. CD4 lymphocyte counts, serum immunoglobulins, and p24 antigenemia were also evaluated. Prior to vaccination concentrations of immunoglobulins were higher and CD4 positive lymphocyte counts were lower in the infected infants than in the noninfected infants. Following primary vaccination, an appropriate antibody response was found in 22 (92%) of 24 uninfected children and in 4 (29%) of 14 infected ones. Mean AT antibody levels were lower in infected than in uninfected infants, with values differing more significantly after the second tetanus toxoid (TT) administration (p values: 0.06, 0.01, and 0.03 after the first, second, and third doses, respectively). Also, uninfected children showed a more than 4-fold rise in specific antibody concentration after the second TT immunization, which was not found in infected infants (1.1-4.28 HU/ml vs 0.27-0.31 HU/ml in uninfected and infected children, respectively). Among the infected children no difference in the AT antibody levels of those with acquired immunodeficiency syndrome (AIDS) and those with non-AIDS status could be detected. In conclusion, our data confirm that symptomatic HIV-1-infected infants have a reduced capacity to sustain an antibody response to recall antigens.