Despite positive results from a Phase I/II trial of its investigational pandemic influenza vaccine, mRNA-1018, Moderna’s award for almost $600 million to accelerate vaccine development will be terminated.
The United States Department of Health and Human Services (HHS) has terminated a $590 million grant previously awarded to Moderna to accelerate the development of pre-pandemic influenza vaccines.1
In a statement released to CNN, as well as other news outlets, HHS Communications Director Andrew Nixon said: “After a rigorous review, we concluded that continued investment in Moderna’s H5N1 mRNA vaccine was not scientifically or ethically justifiable. The reality is that mRNA technology remains under-tested, and we are not going to spend taxpayer dollars repeating the mistakes of the last administration, which concealed legitimate safety concerns from the public.”2
Meanwhile, Moderna has shared positive results from a Phase I/II trial (NCT05972174) of its investigational pandemic influenza vaccine, mRNA-1018, targeting the H5 avian influenza virus subtype. Moderna had previously expected to advance this program into late-stage development. However, with news of the grant termination, the company “will explore alternatives for late-stage development and manufacturing of the H5 program consistent with (its) strategic commitment to pandemic preparedness.”
In a press release, Stéphane Bancel, chief executive officer of Moderna, said: "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 program. These clinical data in pandemic influenza underscore the critical role mRNA technology has played as a countermeasure to emerging health threats."
The Phase I/II study of mRNA-1018 in approximately 300 healthy adults was largely a success, according to Moderna. Following a two-dose regimen, pre-existing immunity at baseline was minimal with only 2.1% of participants showing hemagglutination inhibition (HAI) antibody titers ≥1:40, an HAI titer considered to correlate with protection. Three weeks after the second dose, at day 43 of the study, 97.8% of participants achieved titers ≥1:40 with a 44.5-fold increase of titers from baseline.
Over 1500 participants were enrolled across the entire study program, which was conducted in two parts. Part A evaluated four vaccine candidates: H5N8, H7N9, H5 only, and H7 only, whereas Part B evaluated a single candidate, H5 only-CG. Primary outcome measures included number of participants with solicited local and systemic adverse events (AEs) as well as number of participants with unsolicited AEs.3
HHS awarded Moderna the $590 million grant earlier in January. It was given through the Rapid Response Partnership Vehicle Consortium along with funding from the Biomedical Advanced Research and Development Authority, part of the HHS Administration for Strategic Preparedness and Response.4
According to a press release from HHS at the time, the funding would allow Moderna to “accelerate development of an H5N1 mRNA influenza vaccine that is well matched to strains currently circulating in cows and birds and expands the clinical data supporting the use of mRNA vaccines that may be needed if other influenza strains emerge with pandemic potential.”
In March, Applied Clinical Trials
This termination of Moderna’s grant represents the current administration’s broader focus on mRNA research. HHS Secretary Robert F. Kennedy Jr. has expressed skepticism regarding mRNA vaccine safety and efficacy. Just a few weeks ago, the FDA overhauled its
1. Moderna Announces Update on Investigational Pandemic Influenza Program. News release. Moderna. May 28, 2025. Accessed June 4, 2025.
2. Dillinger K. HHS cancels $590 million contract with Moderna for bird flu vaccine. CNN. May 28, 2025. Accessed June 4, 2025.
3. A Study of mRNA-1018 Pandemic Influenza Candidate Vaccines in Healthy Adults. ClinicalTrials.gov. Accessed June 4, 2025.
4. HHS provides $590 Million to accelerate pandemic influenza mRNA-based vaccine development, enhance platform capability for other emerging infectious disease. Department of Health and Human Services. January 17, 2025. Accessed June 4, 2025.
