Moderna has begun a Phase 3 trial of its mRNA-based bird flu vaccine in the UK and US, enrolling approximately 4,000 participants to test protection against the A(H5N1) strain.
The vaccine, designated mRNA-1018, uses the same messenger RNA technology as Moderna’s Covid-19 shots to instruct cells to produce viral proteins that trigger an immune response.
In the UK, 3,000 participants — half aged over 65 — will receive the vaccine across 26 sites in England and Scotland, with doses administered three weeks apart over a seven-month study period.
The trial is sponsored by Moderna and backed by the National Institute for Health and Care Research (NIHR), following early data showing the jab was generally well tolerated with only mild to moderate side effects and no safety concerns.
Researchers are prioritising enrolment of poultry farmers and individuals with regular bird contact due to their elevated exposure risk, though the study remains open to others meeting eligibility criteria.
For more on this story, see Only write the title, nothing else. Major Trial Launches for Human Bird Flu Vaccine – Key Developments and What It Means for Public Health.
Although A(H5N1) does not yet spread easily between humans, experts warn its evolution in animals — including recent infections in dairy cows and mink — creates a real possibility of human-to-human transmission.
The virus has caused sporadic human cases among farm workers in the US after spreading to cattle, underscoring the need for preemptive vaccine development despite limited sustained person-to-person spread.
Public health officials view the trial as a critical component of pandemic preparedness, aiming to establish efficacy and safety data before any potential shift in viral transmissibility.
Who is eligible to join the bird flu vaccine trial?
The trial encourages poultry farmers and individuals with close contact with birds to enrol, though participation is open to others who meet the study’s criteria in the UK and US.
How does the mRNA bird flu vaccine perform?
The vaccine uses mRNA technology to teach the body to produce specific viral proteins from the A(H5N1) strain, training the immune system to recognise and respond to the virus upon exposure.