Clinical trials for a universal flu vaccine, which would protect against various influenza strains, have started at Duke Health in North Carolina. The study is in the very early stages, currently enrolling participants for phase 1 to test the safety and immune response. The hope is that a universal flu vaccine would eliminate the need to develop new formulations and administer a new vaccine every year.

In the United States, seasonal influenza claims the lives of thousands annually. Although seasonal flu vaccines help control its spread, they do not provide immunity against all strains. Traditional flu vaccines are designed to protect against the three or four most common strains of influenza virus that are circulating each year. However, the flu virus mutates rapidly, so the effectiveness of traditional flu vaccines can vary from year to year. Each year, experts must predict prevalent strains and include them in the seasonal vaccine, but this approach can lead to reduced efficacy if the virus mutates unexpectedly. A universal flu vaccine could overcome these challenges by offering broad protection against various strains and potentially providing long-lasting immunity.

This early-stage trial is part of the Collaborative Influenza Vaccine Innovation Centers program, established by the National Institute of Allergy and Infectious Diseases in 2019 to support the development of longer-lasting and broadly protective flu vaccines. The investigational vaccine, manufactured at the Duke Human Vaccine Institute, utilizes a specific segment of the flu protein hemagglutinin (HA) to elicit a broad immune response. The HA stem, which evolves slowly and remains consistent across different flu types, offers the potential for inducing durable immunity. Unlike the previous vaccine from the Vaccine Research Center, the H1ssF-3928 mRNA-LNP candidate employs a messenger RNA platform. This approach allows researchers to explore different platforms and increase the chances of finding a safe vaccine that confers strong and broad immunity against multiple strains.

More research is needed to determine whether universal flu vaccines will be effective in humans. However, the progress that has been made so far is promising, and it is possible that a universal flu vaccine could be available in the future.