THE ROLE OF VIROLOGICAL AND IMMUNOLOGICAL FACTORS IN MOTHER-TO-CHILD TRANSMISSION OF HIV-1

PROBLEM: More than 90% of human immunodeficiency virus type 1 (HIV-1) infection in children is acquired by mother-to-child transmission. How ever, infection of the child occurs in between 14 and 35% of cases. ME THOD OF STUDY: To understand the mechanisms involved in HN-I transmiss ion, we have investigated the antigenic, molecular, and phenotypic cha racteristics of the virus harbored in infected mothers and their child ren. RESULTS: A clear correlation was observed between the transmissio n of the virus and the isolation of viral variants with a rapidly repl icating and syncytium-inducing phenotype from the mother. Furthermore, non-transmitting mothers were able to neutralize several primary isol ates more frequently than transmitting mothers. The comparison of the viral phenotype and genotype of mother-child pairs showed that the tra nsmitted virus did not have common features, suggesting that transmiss ion is usually not a selective process. CONCLUSIONS: This study sugges ts that transmission is governed by an interaction of both viral and i mmunological factors. The results obtained indicate that different str ategies can be applied for the prevention of transmission.