The United States, European Union, India and South Africa have reached a tentative agreement on key elements of a long-sought limited intellectual property (IP) waiver for COVID-19 vaccines, sources familiar with the deal said Tuesday.

The tentative agreement among the four members of the World Trade Organization (WTO) still needs formal approvals from the parties before it can be considered official, the sources said.

It would apply only to patents for COVID-19 vaccines, which would be much more limited in scope than a broad proposed WTO IP waiver backed by the United States, they said.