US conditions funding to global vaccine group Gavi on dropping mercury-based preservative from shots
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Gavi, helps the world's poorest and lower-income countries buy vaccines, says vaccine safety is its utmost concern.
PHOTO: REUTERS
LONDON - The Trump administration has told global vaccine group Gavi to phase out shots containing the preservative thimerosal as a condition to providing the group with funding, a US official and a Gavi spokesperson told Reuters.
The request, which Reuters is the first to report, is the latest sign of efforts by the administration of US President Donald Trump to influence health policy globally.
Anti-vaccine groups, including one founded by US Health Secretary Robert F. Kennedy Jr, 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.
In June 2025, Mr Kennedy cut US$300 million (S$378 million) in annual funding for Gavi, which helps the world's poorest and lower-income countries buy vaccines to prevent diseases such as measles and diphtheria.
Mr Kennedy, who has long promoted anti-vaccine views contrary to scientific evidence, says the group ignores safety issues with the immunisations it provides.
Gavi says vaccine safety is its utmost concern.
“Until a plan for removal of thimerosal-containing vaccines is developed and the plan initiated, the United States will withhold future new funding,” an official for the US Department of Health and Human Services told Reuters.
The official would not comment on when the request was made, but claimed Gavi has so far refused to develop such a plan.
A Gavi spokesperson confirmed the request to remove thimerosal from its portfolio, and said the group remained in contact with the US government on the subject.
"While we very much hope to find a pathway to welcoming the US back as a donor, any decision related to Gavi’s portfolio would require a decision by Gavi’s board and input from preceding governance committees, which will be guided by scientific consensus," the spokesperson said.
Often used in low- and middle-income countries
Thimerosal is mainly used to ensure that vaccines in multi-dose vials remain stable.
That helps immunisation campaigns in low- and middle-income countries because multi-dose vials are cheaper and simpler to distribute, Gavi and the World Health Organization (WHO) say.
The preservative has largely been phased out in high-income countries, where vaccines usually come in a single-use format, although its use is not prohibited.
Under Mr Kennedy, the US moved last summer to stop the use of influenza vaccines containing thimerosal, representing around 5 per cent of flu shots given in the country, despite US health agencies having declared them safe.
The US official said the request of Gavi aims to bring its policies in low- and middle-income countries in line with the US, Canada and most European nations.
The safety of thimerosal has been studied for decades, after concerns were raised in the 1990s about exposure to mercury in vaccines, according to the WHO.
No compelling scientific evidence has been found to suggest that there is a risk, particularly when compared with the dangers of keeping children unprotected against deadly diseases, the WHO says.
The US request applies to both the remaining US$300 million that the Biden administration had pledged to Gavi with congressional approval, but which is still outstanding, and to any future funding, the official said.
The US previously contributed around 13 per cent 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.
The Trump administration has cut billions of dollars in health funding internationally and withdrawn from the WHO.
The US government has said it is still committed to global health and is pursuing bilateral agreements with countries under Mr Trump's “America First” agenda.
Last week, the US Health Department said a hepatitis B vaccine study in Guinea Bissau would help inform global policy.
The study, funded by the US Centers for Disease Control and Prevention (CDC), is now undergoing further ethical review after international criticism.
The US CDC in December withdrew its longstanding recommendation
