Efficacy of zidovudine and human immunodeficiency virus (HIV) hyperimmune immunoglobulin for reducing perinatal HIV transmission from HIV-infected women with advanced disease: Results of pediatric AIDS clinical trials group protocol 185

Pediatric AIDS Clinical Trials Group protocol 185 evaluated whether zidovud ine combined with human immunodeficiency virus (HIV) hyperimmune immunoglob ulin (HIVIG) infusions administered monthly during pregnancy and to the neo nate at birth would significantly lower perinatal HIV transmission compared with treatment with zidovudine and intravenous immunoglobulin (MG) without HIV antibody. Subjects had baseline CD4 cell counts less than or equal to 500/mu L (22% had counts <200/mu L) and required zidovudine for maternal he alth (24% received zidovudine before pregnancy), Transmission was associate d with lower maternal baseline CD4 cell count (odds ratio, 1.58 per 100-cel l decrement; P = .005; 10.0% vs. 3.6% transmission for count <200 vs. great er than or equal to 200/mu L) but not with time of zidovudine initiation (5 .6% vs. 4.8% if started before vs. during pregnancy; P = .75), The Kaplan-M eier transmission rate for HIVIG recipients was 4.1% (95% confidence interv al, 1.5%-6.7%) and for MG recipients was 6.0% (2.8%-9.1%) (P = .36), The un expectedly low transmission confirmed that zidovudine prophylaxis is highly effective, even for women with advanced HN disease and prior zidovudine th erapy, although it limited the study's ability to address whether passive i mmunization diminishes perinatal transmission.