The first participants in the US and UK have been dosed in a phase 3 study of Moderna’s investigational mRNA-based H5 pandemic influenza vaccine candidate, mRNA-1018, the company announced on 21 April 2026.
This comes amid concerns surrounding the pandemic potential of avian flu, or ‘bird flu’.
Stéphane Bancel, CEO, Moderna, said: “H5 influenza, or bird flu, remains a pandemic threat.
“The start of our phase 3 trial for an H5 influenza vaccine marks a significant milestone in our ongoing efforts to strengthen global pandemic preparedness.”
The phase 3 study will evaluate the safety and immunogenicity of mRNA-1018 in healthy adults aged 18 or above.
It is expected to enrol approximately 4,000 adults across the US and UK, 75% of which are expected to be recruited in the UK.
There will be 26 sites across the UK administering the vaccine, in various clinics across England and Scotland.
The Coalition for Epidemic Preparedness Innovations
The study is supported by Moderna’s collaboration with the Coalition for Epidemic Preparedness Innovations (CEPI).
Dr Richard Hatchett, CEO, CEPI, said: “The first-of-its-kind pivotal trial of an mRNA-based pandemic influenza vaccine underscores the potential of this technology to reshape how we confront emerging pathogens.
“If successful, these efforts could transform our ability to respond swiftly and equitably to one of the world’s most enduring threats.”
Rollout upon study success
If licensed and in the event of an influenza pandemic, Moderna will allocate 20% of its H5 pandemic vaccine manufacturing capacity for timely supply to low- and middle-income countries at affordable pricing as part of its agreement with CEPI.
The UK Health Security Agency said that, although current human risk is low, it will continue to monitor available data.
Dr Richard Pebody, Director of Epidemic and Emerging Infections, UK Health Security Agency (UKHSA), commented: “Although the current risk to the human population of avian influenza remains low, the virus continues to evolve and spread in birds and various animal hosts in the UK and elsewhere.
“UKHSA remains alert to the potential that this pathogen could adapt to spread from person to person, and will continue to monitor all available data.
“This important initiative to trial a new mRNA pandemic influenza vaccine is a key step towards further strengthening our ability to protect people against future influenza pandemics.”
Featured image: asiraj on Adobe Stock
