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IMPAACT 2010 Primary Results Released

The IMPAACT Network is delighted to announce the presentation of important findings from IMPAACT 2010 (the VESTED study) at the 2020 Conference on Retroviruses and Opportunistic Infections (CROI) today.


The International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Network is delighted to announce the presentation of important findings from IMPAACT 2010 (the VESTED study) at the 2020 Conference on Retroviruses and Opportunistic Infections (CROI) today. A NIAID news release related to the presentations is available here.

IMPAACT 2010/VESTED is a Phase III, three-arm, randomized, open-label study of pregnant women with HIV initiating either a dolutegravir (DTG)-containing antiretroviral regimen or an efavirenz (EFV)-containing antiretroviral regimen at 14-28 weeks gestation. When the study began, treatment regimens containing EFV and TDF were commonly recommended and used worldwide. Newer regimens containing DTG were also being added to treatment recommendations but had not been evaluated among pregnant and postpartum women. The study was designed to evaluate whether DTG-containing regimens would be non-inferior to EFV/FTC/TDF with regard to virologic efficacy at delivery and whether rates of adverse pregnancy outcomes, maternal adverse events, and infant adverse events would differ between the regimens.

Findings presented at CROI were based on data collected during pregnancy, through delivery, and through the first 28 days of infant life. Follow-up of women and infants through the first year postpartum is currently ongoing (findings from the postpartum period will be reported separately). Results are described below.

Study Results

A total of 643 pregnant women and their unborn babies were enrolled in IMPAACT 2010/VESTED between January 2018 and February 2019 at 22 IMPAACT sites in Botswana, Brazil, India, South Africa, Tanzania, Thailand, Uganda, the United States, and Zimbabwe. Pregnant women were randomly assigned, in pairs with their babies, to one of three ARV regimen groups: EFV/FTC/TDF, DTG+FTC/TDF, or DTG+FTC/TAF.


Results, presented by Lameck Chinula on behalf of the IMPAACT 2010 Protocol Team, showed that all three ARV regimens were safe and effective in pregnancy. However, the DTG-containing regimens were more effective than the EFV-containing regimen at controlling HIV in pregnancy. This was discovered by comparing the number of mothers in each group who had a low HIV viral load at delivery. Almost all (98%) mothers who received DTG were virally suppressed at delivery, compared to most (91%) mothers who received EFV.

In addition, the regimen containing DTG and TAF had the best pregnancy outcomes. This was discovered by comparing the number of mothers in each group who had an adverse pregnancy outcome (stillbirth, pre-term delivery, infant small for gestational age). About one in four (24%) mothers who received DTG+FTC/TAF had an adverse pregnancy outcome, compared to about one in three (33%) mothers who received DTG+FTC/TDF or EFV/FTC/TDF. Two infants were found to have HIV infection within the first 14 days of life, and no neural tube defects were identified.

These results are only the beginning of what will be learned from IMPAACT 2010/VESTED. The study is expected to be completed in August or September of 2020 and further results will be forthcoming in the future.

For more information about IMPAACT 2010/VESTED, visit or contact