The Trump administration said on Wednesday it will immediately release $600 million in congressionally appropriated funds ​for vaccines for the world's poorest countries after Washington withheld the money ‌over unsubstantiated safety concerns raised by U.S. Health Secretary Robert F. Kennedy Jr.

U.S. Secretary of State Marco Rubio had said in June that it was time to re-engage with the Geneva-based global ​alliance Gavi, which helps the world's poorest countries buy vaccines to protect ​children from diseases such as measles and diphtheria, citing both congressional ⁠concerns and "our goals on global health."

The previous month, Gavi's chief executive Sania ​Nishtar had said Gavi was moving away from vaccines that included a mercury-based preservative ​about which Kennedy had raised concerns.

The U.S. State Department said in a statement on Wednesday the decision to release funds was taken after Gavi committed "to work towards transitioning mercury-containing vaccines and ​expanding access to newer, mercury-free alternatives."

Representatives for Gavi did not immediately respond to ​a request for comment sent late Wednesday night in Geneva.

Anti-vaccine groups, including one founded by ‌Kennedy, ⁠have for decades claimed that thimerosal, a mercury-based preservative used in vaccines, is linked to autism and other neurodevelopmental disorders, despite many studies showing no related safety issues.

Kennedy, a longtime vaccine sceptic, said in June 2025 the U.S. would no longer provide ​any funding - representing ​around $300 million a ⁠year - because Gavi ignored safety. He did not provide evidence to support his claim.

The U.S. previously contributed around 13% of ​Gavi’s funding, and the organisation has embarked on a series ​of cost-cutting ⁠measures to try to address the shortfall, which has been exacerbated by cuts from other high-income nations.

On Wednesday, the State Department said the U.S. expects to resume its ⁠place ​on the Gavi board and that it will ​evaluate any future U.S. support to the group based on "demonstrated performance, accountability, and implementation" of reforms."