Risk adapted transmission prophylaxis to prevent vertical HIV–1 transmission: Effectiveness and safety of an abbreviated regimen of postnatal oral Zidovudine

118 mother infant pairs were treated according to the German-Austrian recommendations for HIV therapy in pregnancy and in HIV exposed newborns between 2000–2010. In the absence of factors associated with an increased HIV–1 transmission risk, children were assigned to the low risk group and treated with an abbreviated postnatal regimen with oral ZDV for 2 weeks. In the presence of risk factors, postnatal ZDV was escalated accordingly.Of 118 mother-infant pairs 79 were stratified to the low risk group, 27 to the high risk group and 11 to the very high risk group for HIV–1 MTCT. 4 children were lost to follow up. Overall Transmission risk in the group regardless of risk factors and completion of prophylaxis was 1.8% (95% confidence interval (CI) 0.09–6.6). If transmission prophylaxis was complete, transmission risk was 0.9% (95% CI 0.01-5.7). In the low risk group receiving two week oral ZDV transmission risk was 1.4% (95% CI 0.01–8.4)These data demonstrate the effectiveness of a short neonatal ZDV regimen in infants of women on stable ART and effective HIV–1 suppression. Further evaluation is needed in larger studies.One of the major achievements of HIV research was the demonstration in the PACTG 076 trial that the administration of zidovudine (ZDV) given orally to the pregnant woman at 14 to 34 weeks gestation, given intravenously to the mother during labour and given orally to the infant for 6 weeks in the absence of breastfeeding reduced the risk of perinatal transmission by 70% [1]. It is not known whether all three arms of this regimen contributed equally to the reduction in risk. With the further introduction of effective antiretroviral therapy (ART) and scheduled caesarean section transmission rates of 1–2% were reported in resource rich countries [2,3]. With increasing progression in the treatment of HIV disease especially with an increasing proportion of HIV infected women receiving combination ART throughout pregnancy, modifications in the interventions to r