An international clinical trial has found that AIDS-fighting antiretroviral drug combinations given to pregnant and breastfeeding women in Botswana, Africa, prevented 99 per cent of the mothers from transmitting he human immunodeficiency virus (HIV) to their infants.
The trial was led by researchers at the Harvard School of Public Health (HSPH).
“This is the lowest rate of mother-to-child transmission recorded in a study from Africa, or among breastfeeding infants,” said lead author Roger Shapiro, Associate Professor of Medicine at Harvard Medical School and Harvard School of Public Health.
The mother-to-child transmission rate in the study was 1.1 per cent when the infants were breastfed to age 6 months.
“Previous interventions using shorter or less comprehensive drug treatment regimens have been unable to get rates below 5 per cent, and without any intervention, the infection rate would be at least 25 per cent by 6 months,” said Shapiro.
The study was also the first randomized clinical trial to compare highly active antiretroviral therapy (HAART) regimens used during pregnancy or breastfeeding.
The article appears today (June 17) in The New England Journal of Medicine . Breastfeeding is normally the best way to feed an infant and is one of the most critical factors for improving child survival in developing nations.
Periods of transmission
A woman infected with HIV, however, can transmit the virus to her child during breastfeeding, as well as during pregnancy, labour and delivery.
The research was part of the Mma Bana Study conducted in southern Botswana as a collaboration between HSPH and the Botswana government to improve health for women and children. The use of HAART to prevent vertical transmission is one of the most successful public health interventions to prevent the transmission of AIDS in pregnancy.
Little has been known, however, about its promise for halting HIV transmission from mother to infant through breastfeeding in areas of the world where formula feeding is neither safe nor feasible, including most of sub-Saharan Africa.
The study compared the suppression of the mother's HIV virus at delivery and throughout breastfeeding among women assigned to receive one of three treatment regimens, according to a Harvard Medical School press release.
Overall, 730 HIV-infected pregnant women were included in the study and most started HAART early in the third trimester of pregnancy. Almost all women achieved viral suppression by delivery, and their virus remained undetectable throughout breastfeeding.
All three HAART regimens consisted of commonly used antiretroviral combinations with three active drugs.
All regimes effective
All HAART regimens used in the study were found to be highly effective at suppressing the HIV virus, said the authors. They also found the HAART regimens used in the study were safe and generally well-tolerated.
The rates of infection with HIV in southern Africa are 3 to 5 times higher than in the rest of sub-Saharan Africa and more than 100 times higher than in the rest of the world. This discrepancy is much greater for women and children.
The Mma Bana Study findings already have influenced WHO guidelines on the use of HAART to prevent mother-to-child HIV transmission. For the first time, WHO recently recommended that all HIV-infected mothers or their infants take antiretroviral drugs while breastfeeding to prevent HIV transmission.
