type: timeline_event
On May 28, 2025, the Department of Health and Human Services notified Moderna that it was canceling contracts worth $766 million to develop, test, and license vaccines for flu subtypes that could trigger future pandemics, including the dangerous H5N1 bird flu virus. The cancellation came as H5N1 had spread to 1,072 dairy herds, more than 173 million poultry, and caused 70 human cases with one death in the United States.
Moderna had received the initial HHS contract for an H5 vaccine in a $176 million base award in July 2024 amid a rising number of H5N1 infections in U.S. residents, mostly agricultural workers. On January 17, 2025, in the final days of the Biden administration, officials announced a $590 million contract expansion to fund the development of vaccines against potential pandemic flu viruses. HHS Communications Director Andrew Nixon justified the cancellation by claiming that "after a rigorous review, we concluded that continued investment in Moderna's H5N1 mRNA vaccine was not scientifically or ethically justifiable" and that "mRNA technology remains under-tested."
The cancellation was particularly damaging because it forfeited the government's right to pre-purchase vaccine doses and revoked a pandemic preparedness designation that would have allowed rapid production in an emergency. No other flu vaccine production approach can produce doses with the speed of the messenger RNA platform used by Moderna, meaning the cancellation eliminated the nation's fastest-response pandemic vaccine option. The vaccine platform was viewed with deep suspicion by Health Secretary Robert F. Kennedy Jr. and his political base, despite Moderna's phase 1/2 trial of mRNA-1018 showing that 97.8% of participants achieved protective antibody titers with a robust immune response and safety profile.
Congressional Democrats had sent Kennedy a letter on April 1, 2025, questioning the Secretary's willingness to let avian flu "run through the flock" rather than attempt to mitigate the outbreak. On June 11, 2025, Rep. Raja Krishnamoorthi led Members of the Subcommittee in sending a letter demanding information surrounding the decision to cancel the Moderna contract amid an uncontrolled avian flu outbreak, expressing concern that Kennedy's "longstanding vaccine hesitancy—including your statement that 'there's no vaccine that is safe and effective'—appears to be influencing federal policy."
Public health experts condemned the cancellation as a significant blow to the country's capacity to respond to pandemic influenza. Alexandra Phelan, an associate professor at Johns Hopkins Bloomberg School of Public Health, stated: "We have immediately, quite clearly, a series of decisions or lack of decisions, that are undermining US public health and comparatives when it comes to vaccines." Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia, told Axios that the cancellation, combined with recent workforce reductions at health agencies, reflected "just a gradual sort of dismembering of the public health service."
The cancellation of the Moderna H5N1 vaccine contract represented the most concrete manifestation of how RFK Jr.'s anti-vaccine ideology was being translated into federal policy with potentially catastrophic consequences. By eliminating the nation's most advanced pandemic flu vaccine program while H5N1 continued to spread through American agriculture and had already killed one American, Kennedy deliberately dismantled pandemic preparedness infrastructure to satisfy his ideological opposition to mRNA vaccines. This decision prioritized anti-vaccine political rhetoric over practical preparation for a potential influenza pandemic, leaving the United States without its fastest-response vaccine option in the face of an evolving viral threat that had already demonstrated the ability to cause severe illness and death in humans.