Gilead Sciences will allow some of its AIDS drugs to be made by generic manufacturers, potentially increasing their availability in poor countries, particularly in Africa, according to the Associated Press.

In the first deal of its kind, the pharmaceutical company has agreed to allow four of its AIDS drugs to be made by generic drug companies at a cheaper cost in return for a small proportion of royalties, United Nations health officials said.

The move is particularly important because it includes tenofovir and emtricitabine, which have emerged as important components of AIDS therapy and new prophylaxis regimens, like vaginal microbicides for women and once-a-day pills protecting gay men, according to The New York Times. Many poor countries now have only older drugs, some of which have harsh side effects.

Most of the 33 million people worldwide who have HIV, the virus that causes AIDS, live in Africa. One of the drugs will also be used to treat people with hepatitis.

The deal was negotiated by the new international Medicines Patent Pool, reported AP, the part of a U.N.-led partnership that raises money for AIDS, tuberculosis and malaria by things like taxing airplane tickets. Among the partnership's 29 member countries, only Chile, France, Korea, Mali and Niger are actually implementing the airline tax.

"We will continue to work with Gilead and others to expand access to all people living with HIV in developing countries," said Ellen Hoen, executive director of the Medicines Patent Pool.

Gilead will receive 3% to 5% royalties on its four drugs, which will be supplied to about 100 countries. Until now, its drugs have been mainly sold in rich countries, and profits from the new deal are expected to be a tiny fraction of those Gilead gets from the West.

Typically, patients in poor countries have to wait for years until the patents expire on new drugs before they can be made more cheaply by generic companies.

But some 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.

"This agreement is an improvement over what other big pharma companies are doing to ensure access to their patented AIDS medicines in developing countries," said Michelle Childs, a director at Doctors Without Border's campaign for access to essential medicines. Still, she warned caution was necessary and that the new deal "should not become the template for future agreements."

The pool was created last year, but drug makers have resisted it, wanting to control quality and protect rights to future profits from middle-income countries, according to the Times report. Until this week, the only participant was the National Institutes of Health, which turned over a partial patent on an obscure AIDS drug.

“This is a great achievement,” said James P. Love, a campaigner for lower drug prices who first proposed a pool in 2002. “The other drug companies didn’t want Gilead to sign anything, and this will put pressure on them.”

Other major drug makers including Johnson and Johnson, Abbott Laboratories and Merck have so far declined to formally negotiate with the U.N.-led group.