Gilead Sciences says it will allow some of its AIDS drugs to be made by generic manufacturers, potentially increasing their availability in some poor countries.

In a statement issued on Tuesday, United Nations health officials announced Gilead has agreed to allow four of its AIDS drugs to be made by generic drug companies at a cheaper cost. Most of the 33 million people worldwide who have HIV, the virus that causes AIDS, live in Africa.

But other experts questioned whether the deal went far enough and pointed out it specifically excludes manufacturers in Thailand and Brazil, which both produce large amounts of generic drugs.