PHARMACOLOGICAL AND METHODOLOGICAL BASES FOR THE EVALUATION OF TREATMENTS AIMED AT PREVENTING MOTHER-TO-CHILD TRANSMISSION OF THE HUMAN-IMMUNODEFICIENCY-VIRUS

Vertical transmission is responsible for the overwhelming majority of cases of human immunodeficiency virus (HIV) infection in children. Whe ther vertical transmission of the HIV occurs predominantly in utero, d uring delivery, or during breast feeding remains unsettled. Measures o f potential usefulness for preventing vertical transmission of the HIV include contraception or elective termination of pregnancy in HIV-pos itive women, and delivery by cesarean section followed by bottle feedi ng of infants born to HIV-positive mothers. Preclinical and clinical s tudies of the prevention of vertical HIV transmission have been carrie d out with anti-HIV immunoglobulins, CD4-IgG or immunoadhesine, interf eron alpha, zidovudine, and didanosine. Drugs with the greatest preven tive potential may be zidovudine (currently under evaluation in a Phas e III, multicenter, randomized, double-blind, placebo-controlled ACTG study [ACTG 076]) and immunoadhesine CD4-IgG (which has yielded promis ing results in animal models). There is a need for additional biologic al and epidemiological data on vertical HIV transmission. Clinical tri als focusing on efficacy and safety are at a very early stage and will have to solve a number of methodological and ethical problems. They s hould be conducted using methods similar to those of the ACTG 076 tria l. Evaluation of the risk/benefit ratio and cost-effectiveness of thes e treatments will need to be performed with the goal of reducing the i ncidence of HIV infection in children.