The US Department of Health and Human Services (HSS) has terminated a contract previously awarded to Moderna to help advance a vaccine candidate targeting avian influenza, more commonly known as bird flu.
The move to withdraw previously promised funding signals the health agency's latest shift away from vaccine dependence, headed by vaccine-sceptic Robert F Kennedy (RFK) Jr.
Moderna won the contract in July 2024, with an initial $176m grant given by the Biomedical Advanced Research and Development Authority (BARDA), the agency responsible for developing and stockpiling medical countermeasures in the US. The HHS then topped this up with $590m, giving a total contract value of $766m.
The funds were intended for Moderna to use in late-stage development of its mRNA vaccine, dubbed mRNA-1018, against the H5 influenza virus, a family of pathogens that can infect humans if transmitted from birds.
Moderna stated it “expected to advance the programme to late-stage with the HHS; however, today, received notice that HHS will terminate the award for the late-stage development and right to purchase pre-pandemic influenza vaccines”. The company will now explore alternatives to continue mRNA-1018’s clinical journey.
The funding axe comes despite Moderna reporting positive interim data from a Phase I/II clinical study (NCT05972174) evaluating the safety and immunogenicity of mRNA-1018. Across 300 healthy adults aged 18 years and older, the candidate demonstrated a “rapid, potent and durable immune response”. Three weeks after a second vaccination, 97.8% of participants achieved immunity as measured by haemagglutination inhibition (HAI) antibody titers. Moderna said the vaccine was generally well-tolerated, with adverse reactions limited to mild and moderate side effects.
H5 bird flu is widespread in wild birds and is causing ongoing outbreaks in poultry and US dairy cows. The US Centers for Disease Control and Prevention (CDC) has said the public health risk “is low”, though the first human died as a result of the virus in January 2025.
"While the termination of funding from HHS adds uncertainty, we are pleased by the robust immune response and safety profile observed in this interim analysis of the Phase I/II study of our H5 avian flu vaccine, and we will explore alternative paths forward for the programme,” said Moderna’s CEO Stéphane Bancel.
"These clinical data in pandemic influenza underscore the critical role mRNA technology has played as a countermeasure to emerging health threats.”
The contract termination follows another development in Moderna’s vaccine pipeline earlier this week. The company voluntarily withdrew its application to the US Food and Drug Administration (FDA) for approval of its Covid-19 and flu combination vaccine. Although not providing a reason, Moderna said it would resubmit later this year with bolstered data from its influenza vaccine mRNA-1010, currently in a Phase III trial (NCT06602024). The HHS contract did not include the development of this vaccine, though it is unclear whether other influenza programmes at Moderna will be affected if internal funding is reallocated.
Earlier this week, RFK Jr announced that the CDC would no longer recommend Covid-19 vaccines to healthy children and pregnant women. This was the first major shake-up to current vaccine schedules in the US by the current Trump administration, having previously targeted candidates still in development such as Moderna’s contract.
