The decision, which halts a key project targeting the H5N1 avian influenza strain, marks a notable policy reversal in the nation’s pandemic preparedness efforts.
The contract, originally awarded under the Biden administration, included $590 million in January to expand Moderna’s clinical trials and explore up to five new influenza subtypes.
An additional $176 million had previously been committed by the Department of Health and Human Services (HHS) in 2024 to complete development and testing of the mRNA-based vaccine.
Today we announced an update on our investigational pandemic influenza program. Learn more: https://t.co/l2J7ipQ95Q. pic.twitter.com/fcmovMqfmg
— Moderna (@moderna_tx) May 28, 2025
Moderna confirmed the cancellation on Wednesday, stating that it still intends to pursue alternative paths for advancing the vaccine’s development and manufacturing. Shares of the company remained flat in after-hours trading.
A spokesperson for HHS said a “comprehensive internal review” had determined the Moderna project no longer met the federal agency’s “scientific standards or safety expectations” to justify continued public investment.
The spokesperson did not provide further detail on the nature of the review’s findings.
The decision comes as the H5N1 strain continues to circulate globally, having infected at least 70 people in the past year—primarily farm workers—while also spreading through cattle herds and poultry flocks.
Dr Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, criticised the cancellation, warning that the government was “discarding what could be one of the most effective and rapid tools” to contain a potential outbreak.
He contrasted the move with former President Donald Trump’s Operation Warp Speed, which expedited COVID-19 vaccine development.
BREAKING: HHS just killed a $600M Moderna contract for pandemic flu vaccines.
The platform: mRNA—the fastest we have against threats like H5N1.
The reason? RFK Jr.’s skepticism.
The risk? Deadly delays when the next pandemic hits. pic.twitter.com/x89l1vFqQg
— Carolyn Barber, MD (@cbarbermd) May 28, 2025
Health Secretary Robert F. Kennedy Jr. has also drawn criticism in recent months for his scepticism of vaccine deployment.
In a controversial television appearance earlier this year, he suggested that poultry farmers should allow avian flu to spread unchecked to observe natural resistance in chickens.
Despite the setback, Moderna reported encouraging interim results from an ongoing mid-stage trial evaluating the safety and immune response of its H5 vaccine candidate.
The company has been relying on revenue from next-generation mRNA vaccines—including its bird flu and COVID-flu combination shots—as demand for its COVID-19 vaccine continues to decline.
The cancellation reflects shifting priorities within the federal government and highlights growing scrutiny of pandemic-related funding decisions made during the previous administration.