By Jim Thomas, Friday, May 22, 2026
Gavi, the global vaccine alliance, informed the U.S. government Thursday it will expedite its move away from vaccines containing thimerosal, a mercury-based preservative, to unlock roughly $600 million in frozen congressional funding that Health and Human Services Secretary Robert F. Kennedy Jr. has withheld over vaccine-safety concerns.
The funds expire September 30, and the alliance warned immunization campaigns in developing nations could face severe disruption without them.
The offer, routed to HHS through Sen. Jeanne Shaheen, D-N.H., the ranking member of the Senate Foreign Relations Committee, marks the clearest break yet in a monthslong standoff.
Shaheen has been working both sides, pressing Kennedy to release money Congress appropriated for fiscal years 2025 and 2026 while pushing Gavi to address his objections to thimerosal.
The alliance, which the United States helped found a quarter-century ago, relies on Washington for a significant portion of its budget.
Kennedy’s response remains uncertain. HHS spokesperson Andrew Nixon stated the department is “cautiously optimistic” ongoing discussions could yield greater transparency, accountability, and a constructive path forward.
Shaheen’s statement was direct: If the funds do not reach Gavi, she said, “we would see a resurgence of deadly infectious diseases that would make Americans and the world less safe.”
Gavi spokesperson Olly Cann explained the alliance’s board moved in 2024 to retire two thimerosal-containing vaccines in favor of newer formulations that protect against more diseases or strains, none of which contain the preservative.
On Thursday, Gavi provided HHS with a phase-out timeline, a list of studies supporting its program, and a written commitment that no federal funding will be used for thimerosal-containing shots, according to Shaheen’s office.
Thimerosal has been in use since the 1930s as a preservative to keep multidose vials sterile—a critical format in regions with limited refrigeration capacity. U.S. manufacturers removed it from pediatric vaccines by 2001, though it remains in some flu shots. The Centers for Disease Control and Prevention states that research has found no link between thimerosal and autism.
In his 2014 book on the subject, Kennedy argued there is broad scientific agreement that thimerosal is “immensely toxic to brain tissue.” His skepticism has influenced certain federal policy decisions but faced pushback. A vaccine advisory panel he appointed last June recommended ending thimerosal use in the United States, yet five months ago in Boston, U.S. District Judge Brian Murphy ruled the panel had been improperly seated under the Federal Advisory Committee Act and stayed its votes, leaving the recommendation in legal limbo.
Cann added that restoring U.S. funding would allow Gavi to “save hundreds of thousands of lives” and help maintain affordable vaccine pricing domestically.
Shaheen credited Kennedy for honoring a pledge he made at an appropriations hearing last month and Gavi for “acting in good faith.”
