Breastfeeding women can reduce the risk of HIV transmission to infants using an extended-dose regimen of nevirapine, according to an article released on July 25, 2008 in The Lancet.

While highly active anti-retroviral therapy (HAART) can prevent vertical transmission when administered to pregnant women, but access to this therapy can be limited in certain regions where resources are limited. Barring this, mothers can minimize the risk of transmitting the disease to their children by finding safe infant feeding alternatives. When these are not available, a single dose of the antiretroviral nevirapine can be administered to mothers and children within 72 hours of birth to reduce the transmission risk.

To explore another potential method, Professor Robert Bollinger and colleagues at Johns Hopkins University, Addis Ababa University, BJ Medical College, the National AIDS Research Institute in India, and Makerere University performed three randomized trials in Ethiopia, India, and Uganda. They hoped to determine whether nevirapine, when administered daily to infants up to six weeks old, could decrease HIV transmission via breastfeeding.

HIV-infected, breastfeeding mothers were randomized to one of two groups: a single-dose nevirapine (SDN), with 200 mg nevirapine administered to the women in labor, and 2 mg/kg given to newborns after birth; or, extended-dose nevirapine (EDN), which had the SDN treatment but an additional 5 mg administered daily between days 8 and 42 (6 weeks) for the infant. The researchers subsequently examined the occurrence of HIV infection in the newborns at 6 months of age in infants who had tested HIV-negative at birth.

In total, 986 SDN infants and 901 EDN infants were included in the study. At six weeks, 54 SDN infants (5.5%) and 25 EDN children (2.8%) tested HIV positive, forming a statistically significant reduction in risk of 46% for the EDN group over the SDN group. At 6 months, 87 SDN children (8.8%) and 62 EDN children (6.9%) tested HIV-positive, a difference which is not statistically significant.

The authors conclude with the positive results of the trial, with ideas for future improvement: “Although a 6-week regimen of daily nevirapine might be associated with a reduction in the risk of HIV transmission at 6 weeks of age, the lack of a significant reduction in the primary endpoint — risk of HIV transmission at 6 months — suggests that a longer course of daily infant nevirapine to prevent HIV transmission via breast milk might be more effective where access to affordable and safe replacement feedings is not yet available and where the risks of replacement feeding are high.”

Dr Jeffrey Stringer and Dr Benjamin Chi, University of Alabama at Birmingham, working from The Centre for Infectious Disease Research in Zambia (CIDRZ), contributed an accompanying comment in which they say: “Extended infant prophylaxis with nevirapine is simple enough to be implemented almost anywhere. It represents a long-awaited, if partial, solution to a mother’s impossible choice. We should not delay.”

However, it should be noted that one co-principal investigator from India who was involved in the study disagrees with the way the paper was interpreted and presented. Further details, including a letter from the investigator and a comment given by the editors can be found in the same issue of the Lancet.

Extended-dose nevirapine to 6 weeks of age for infants to prevent HIV transmission via breastfeeding in Ethiopia, India, and Uganda: an analysis of three randomised controlled trials
Six Week Extended-Dose Nevirapine (SWEN) Study Team
Lancet 2008; 372: 300-13
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Written by Anna Sophia McKenney