Early testing of experimental AIDS vaccines in teenagers may be ethically justified in countries where the disease is spreading quickly, but the risks of such trials may not outweigh the benefits in the US, an FDA panel determined this week, according to Bloomberg News.

The advisory committee is reviewing ways to improve research guidelines for clinical trials in children, and began looking at ethical as well as medical questions that would arise in developing treatments for disorders such as asthma, finding medical uses for stem cells and creating AIDS vaccines.

“There was agreement that AIDS trials in adolescents should take place in countries where adolescents are at higher risk for AIDS and that’s in other countries,” including in Africa, Norman Fost, a pediatrics professor at the University of Wisconsin in Madison, and chairman of the panel meeting this week in Gaithersburg, Maryland.

Testing AIDS vaccines grew controversial last fall, when Merck was forced to halt a study after 49 people who received the experimental med became infected with HIV, compared with just 33 people in a group that were innoculated with a placebo.

Researchers had considered adding adolescents to another study of the Merck vaccine in Africa, according to Alan Fix, a panel member who is chief of the Vaccine Clinical Research Branch at the NIH. And the issue was still under FDA consideration when the results from the Merck trial, called STEP, became public, and the African test was also halted. “There was interest in seeing how this could be done,” he tells Bloomberg. “Then the STEP results came out, so it became a non-issue.”

Congress passed legislation in 2002 granting drugmakers extended patents on medicines that have been tested in children and mandating that the FDA hire a pediatric ethicist to push for safe medical research in children, Bloomberg notes.

But at the same time, scientists and companies are discouraged from doing research on children that poses any significant risks because kids have limited legal standing and mental ability to make decisions for themselves, Bloomberg adds.