Short-Course Regimen of AZT Proven Effective in Reducing Perinatal HIV Transmission: Offers Hope for Reducing Mother-to-Child HIV Transmission in Developing World
In an announcement that has important implications for many developing nations, the Centers for Disease Control and Prevention (CDC) stated today that a short course of AZT given late in pregnancy and during delivery reduced the rate of HIV transmission to infants of infected mothers by half and is safe for use in the developing world. The Ministry of Public Health of Thailand (MOPH), who conducted the study in collaboration with CDC, announced the results earlier today in Thailand.
The findings, from a preliminary analysis of data from the CDC/MOPH collaborative study, offer real hope to many developing nations that previously had no realistic therapy options to prevent HIV-infected pregnant women from transmitting infection to their babies.
We are very fortunate in the U.S. and Europe to have been in a position to offer preventive therapy to HIV-infected pregnant women for several years, and thousands of infections in infants have been prevented as a direct result, said HHS Secretary Donna E. Shalala, "Now we are a step closer to seeing the kind of progress that we've made at home extended to the developing world."
Prior to these findings, the only AZT regimen proven effective for perinatal HIV prevention was essentially out of reach for the countries in which over 90 percent of HIV infections occur.
The AZT regimen used in the U.S. is costly and requires several months of treatment for the mother and the infant and an intravenous dose that is not feasible in many developing countries. In order for policy makers in developing nations to provide HIV-infected women a preventive therapy, they urgently needed conclusive scientific evidence that there is a practical treatment regimen that is safe and more effective than what they have been able to provide which, tragically for most, has been no preventive therapy at all.
By using a much shorter course during pregnancy, an oral dose rather than an intravenous dose during delivery, and no infant dose, we evaluated a regimen that could be realistically implemented in developing nations," said Dr. Helene Gayle, Director of CDC's National Center for HIV, STD, and TB Prevention. "Now that the regimen has been proven safe and effective in Thailand, these findings offer hope of extending perinatal prevention to HIV- infected women throughout the developing world."
The Thailand study was one of two CDC collaborative perinatal HIV prevention studies. The CDC studies, conducted with the Ministries of Health in Bangkok, Thailand and Abidjan, Cote d'Ivoire, were part of an international collaborative research effort coordinated by the Joint United Nations Programme on HIV/AIDS (UNAIDS) to help identify practical solutions for the developing world.
The Thailand study, which began enrollment in 1996, provides the first conclusive scientific data on the preventive effectiveness of a short-course regimen of AZT.
Although final data are not yet in, CDC has now received conclusive interim data from Thailand. Enrollment into the study has been completed and over 90 percent of the data have now been reviewed by CDC and the independent Data Safety and Monitoring Board (DSMB) overseeing the research. Because this regimen has proven both safe and effective, the placebo-control component of CDC's Abidjan study is no longer necessary. Therefore, CDC and its collaborators have begun offering all pregnant women enrolled in the Abidjan study the short-course AZT regimen. Research collaborators worldwide are currently being notified of the findings. In a joint statement released today by UNAIDS, the National Institutes of Health (NIH) , and the French National Agency for AIDS Research (ANRS), it was announced that an international meeting will be soon be held to discuss the far-reaching scientific and policy implications of these findings.
"As the international health community now faces the challenges of making this prevention opportunity a reality for HIV-infected women worldwide, the really hard work begins," said Dr. Kevin DeCock, Director of the Division of HIV Prevention, NCHSTP. "The remarkable news is that we begin with the first conclusive evidence that simpler, practical therapies can make a difference."
CDC stressed that these studies were not designed to address perinatal prevention needs in the U.S. and other industrialized nations. Because HIV-infected pregnant women in the U.S. already have access to the more effective longer treatment regimen, recommendations for perinatal HIV prevention in the U.S. will not change.