A randomized control trial of an Ultra-Short zidovudine regimen in the prevention of perinatal HIV transmission in rural Zimbabwe

OBJECTIVE To assess the practicality and effectiveness of an Ultra-Short zidovudine regimen for prevention of perinatal HIV transmission in rural Zimbabwe. DESIGN Double-blinded placebo-controlled randomized clinical trial. SETTING The Salvation Army Howard Hospital, a district hospital in rural Zimbabwe. SUBJECTS 222 HIV positive pregnant women presenting for antenatal care prior to 36 weeks were randomized. Twenty nine women were lost to follow up. INTERVENTION In the Thai regimen, mothers received zidovudine (300 mg po bid) from 36 weeks gestation until labour, and zidovudine (300 mg po q3h) during labour, and the neonates received a placebo. In the Ultra-Short regimen, the mothers received a placebo from 36 weeks to labour, then zidovudine (300 mg po q3h) in labour. The neonates received zidovudine (2 mg/kg po qid) for the first three days of life. MAIN OUTCOME MEASURE Infant HIV RNA status at six weeks of life. RESULTS Results were available for 90 infants from the Thai group and 89 infants from the Ultra-Short group. Infant HIV seroconversion rates at six weeks of life were 18.9% (95%CI 10.8 to 27.0) with the Thai regimen, and 15.7% [95% Confidence Interval (CI) 8.1 to 23.4] with the Ultra-Short regimen. The upper bound of seroconversion in the Ultra-Short group was lower than the 25% seroconversion boundary that was specified to show equivalence. CONCLUSIONS Although the Ultra-Short regimen has equivalent efficacy to the Thai regimen, it also has many practical advantages. Ultra-Short is thus a preferable protocol.