PROMISE-ZERO

The challenge

The babies of mothers living with HIV are at risk of acquiring HIV while in the womb and during breastfeeding. With more pregnant women receiving antiretroviral therapy during pregnancy, leading to effective viral suppression, HIV transmission during breastfeeding is becoming the most common route of mother-to-child transmission. This can happen because HIV is inadequately suppressed, or mothers acquire HIV during pregnancy or breastfeeding.  

The EDCTP-funded PROMISE-EPI study assessed whether at-risk infants could be identified when mothers bring their babies for routine vaccination at 6–8 weeks. Point-of-care tests for viral load in mothers and HIV testing of infants were used to identify babies who had acquired HIV or were at risk of infection, so that they could be given antiretrovirals throughout breastfeeding. The study found that use of this approach, tested in Burkina Faso and Zambia, led to almost no cases of HIV transmission during breastfeeding. 

The project

The follow-on PROMISE-ZERO project, funded by Global Health EDCTP3, is extending these encouraging findings. The project is exploring whether the same approach can be applied in remote areas of Zambia. It is also extending follow-up to 18 months after birth, by which time more than 80% of mothers will have ceased breastfeeding. 

The project is recruiting pregnant women living with HIV and their infants at a 6–8-week vaccination visit at 40 rural and urban sites in two provinces of Zambia. At large maternal and child health centres, point-of-care HIV testing equipment will be installed. Where this is not possible, district-level mobile teams will organise point-of-care testing to assess viral load and infant infection status. Alternatively, blood samples will be collected and transported to health centres for analysis, with results returned to facilities so that antiretroviral therapy can be initiated when necessary.  

The project will use a single-drug antiretroviral treatment for at-risk infants (lamivudine), which is affordable and readily available, and a simpler option than the triple-drug therapy currently recommended in Zambia. 

As well as infection rates in comparison with usual care, the study will explore the factors affecting the implementation of the new approach in the different settings. A cost-effectiveness analysis will also be carried out. 

Impact

he PROMISE-ZERO project will determine whether point-of-care testing of mothers and babies at vaccination visits is an effective strategy for preventing mother-to-child transmission of HIV during breastfeeding. It will: 

• Provide global and national policymakers with evidence on effectiveness and cost-effectiveness to inform policymaking.
• Show whether a simplified antiretroviral regimen is effective at preventing HIV transmission in infants; this could lead to a shift in national policy, reducing the risk of adverse events and saving money.
• Provide insights into the key factors to consider to ensure the successful implementation of the new approach. 

If the new strategy is found to be effective, its implementation could further reduce mother-to-child transmission of HIV, potentially even helping to achieve complete elimination of transmission during breastfeeding.