A new Harvard School of Public Health (SPH) study could significantly improve AIDS prevention techniques in developing countries. It will be published this week in the New England Journal of Medicine.

Researchers showed that current methods of combating AIDS transmission to babies, which many developing countries cannot afford, can be made simpler and less expensive by reducing the length of the treatments.

"This is a large step forward in reducing pediatric AIDS," Dr. Duane Alexander, director of the U.S. National Institute of Child Health and Human Development said in a press release.

The currently accepted method for preventing HIV transmission from mother to child requires three to sixth months of treatment for the mother and child with the drug zidovudine (AZT). This regimen, while effective in advanced nations, is not accessible to the impoverished areas most stricken by AIDS.

SPH researchers found that the shorter AZT treatment, although not quite as effective, can still reduce perinatal transmission--and at one-fifth the usual cost of $1,000.

"The less-expensive alternative could provide millions of women with treatment that could spare thousands of babies from being infected with the AIDS virus," Alexander said.

While AZT's efficacy in preventing HIV transmission is well established, the SPH study marks the first time researchers have considered the optimal duration of treatment, said Dr. Marc Lallemant, the study director.

Ninety-five percent of the 1,500 infants infected with HIV live in countries too poor to mount an effective prevention effort, according to the press release. But with shorter and less expensive treatments now proven feasible, prevention efforts will be boosted.

"The study will give these countries more treatment options," said Dr. Lynne M. Mofenson, the associate branch chief for clinical research in the pediatric, adolescent and maternal AIDS branch at National Institute of Child Health and Human Development.

The government in Thailand, where the study was conducted, should soon implement policy changes based on the study, according to Lallemant.

"The Thai government is modifying their treatment recommendation to be based on what this study shows," Mofenson said.

With this new treatment option, transmission rates in Thailand should decrease, according to Mofenson.

Treatment will not change in the United States and other developed countries that can afford the more elaborate standard regimen, according to Mofenson.

The full study will be printed in the October 5 New England Journal of Medicine.