Moderna Launches First mRNA-Based H5N1 Bird Flu Vaccine Phase 3 Trial with CEPI Backup
Moderna has initiated a late-stage Phase 3 clinical trial of its experimental avian influenza vaccine, mRNA-1018, marking the first time a pandemic bird flu vaccine utilizing messenger RNA technology has reached this advanced stage of human testing. The study is enrolling approximately 4,000 healthy adults across the United States and the United Kingdom.
Funding and Policy Context
The trial's launch highlights a major shift in public health funding and government relations:
- The Federal Contract Cancellation: In May 2025, U.S. Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. canceled more than $700 million in federal contracts with Moderna that had been earmarked for avian influenza vaccine development.
- CEPI Steps In: To keep the program alive, the Coalition for Epidemic Preparedness Innovations (CEPI) stepped in with a $54 million investment to fund the late-stage development of mRNA-1018.
- Global Access Commitment: As part of the CEPI funding agreement, if mRNA-1018 is approved and an H5N1 influenza pandemic is declared, Moderna has committed to reserving 20% of its vaccine manufacturing capacity to supply low- and middle-income countries (LMICs) at affordable prices.
Clinical and Regulatory Path
Moderna's mRNA-1018 targets the highly pathogenic avian influenza (HPAI) H5N1 strain. The company plans to support its regulatory filings for mRNA-1018 by leveraging safety and immunogenicity data from its seasonal influenza vaccine candidate, mRNA-1010. mRNA-1010 is currently undergoing regulatory reviews in the United States, the European Union, Canada, and Australia.
This development represents a critical milestone in pandemic preparedness, offering a potentially faster-to-scale alternative to traditional egg-based or cell-based influenza vaccines in the event of a bird-to-human spillover crisis.