Virus samples will be shared globally in exchange for vaccines produced from them under a landmark deal to improve preparedness for a flu pandemic, diplomats at the World Health Organization said Saturday.

Negotiators ended an all-night session with a draft agreement accepted by all countries, including the United States, which was the last to join the consensus, they said.

Health ministers were expected to adopt the framework deal, which lays down participation by the drug industry, at the WHO’s annual meeting being held May 16-24.

“The negotiations are finished. The framework was agreed,” an aide to Mexico’s ambassador Juan Jose Gomez Camacho, co-chairman of the closed-door talks, told Reuters.

Countries would share virus samples with the WHO’s network of laboratories in return for affordable vaccines derived from them. The industry has pledged to donate drugs and know-how, covering half of the $58 million annual cost of boosting defenses in the poorest nations, according to senior envoys.

Negotiations began four years ago among the WHO’s 193 members after the deadly H5N1 bird flu virus emerged in southeast Asia. A year later, Indonesia stopped sharing flu virus samples with the WHO’s network, demanding its share of vaccines.

Indonesia’s delegation supported the consensus reached in the round of talks this week, diplomats said.

During the H1N1 swine flu pandemic in 2009-2010, many developing countries complained that they had no life-saving antivirals or vaccines to combat the new virus.

The WHO helped distribute 78 million vaccines, donated by rich nations and drug makers, to 77 developing countries, but regulatory and other hurdles slowed the process.

The pharmaceutical industry has pledged to step up its role.

“Industry agreed what its role will be. They will be able to choose between donations and intellectual property,” a diplomatic source told Reuters.

This meant drug companies could donate significant amounts of vaccines or antivirals, or transfer technology for manufacturing pandemic vaccines, he said.

Drug company executives say current production capacity for pandemic flu vaccine is 1.1 billion doses. GlaxoSmithKline, Novartis and Sanofi-Aventis are among the major flu vaccine makers.

Under the deal, 10 percent of production would be earmarked for developing countries, diplomats said. But the WHO would decide where the doses were best deployed to combat outbreaks.

“It gives flexibility to the WHO to think strategically on how resources should be spent,” a senior diplomat said.