Researchers have discovered a method to develop a universal flu vaccine.

Influenza vaccines have long been the first line of defense against the disease, but their use comes with significant challenges. These vaccines are designed to combat specific strains of the virus, which change rapidly each year. As new strains emerge, the protection offered by these vaccines quickly diminishes, necessitating annual updates and complicating the fight against potential epidemics and pandemics.

For this reason, scientists are striving to develop influenza vaccines that could protect against multiple virus strains, eliminating the need for yearly updates.

A new study published in the journal NPJ Vaccines by researchers from Pirbright in collaboration with the University of Oxford provides fresh evidence supporting the feasibility of developing a universal flu vaccine.

Instead of focusing solely on antibodies—proteins that help the immune system combat infections—a strategy was employed to activate T cells, another component of the immune system capable of recognizing and responding to various influenza viruses. Furthermore, the research team explored the potential of aerosol vaccines delivered directly to the respiratory tract, a powerful method for stimulating the immune response.

During the study, scientists immunized pigs previously infected with the pH1N1 virus using aerosol viral vaccines (ChAdOx2 and MVA). Results indicated that the T-cell response induced by aerosol immunization could provide significant protection.

The pig model is particularly valuable in influenza research, as pigs are major natural hosts of influenza A viruses and share many physiological and immunological similarities with humans.

“This research highlights the importance of targeting the respiratory tract with aerosols to stimulate local immunity and prevent severe disease,” says Professor Elma Tchlian, head of the Mucosal Immunology Group at Pirbright. “This approach holds great significance for both medicine and veterinary science, emphasizing the potential of respiratory vaccines against influenza and other respiratory pathogens.”

“To our knowledge, this is the first evidence that the T-cell response in the lungs, triggered by aerosol immunization, is protective,” states Dame Sarah Gilbert, Professor of Vaccinology at the University of Oxford’s Institute of Pandemic Sciences. “We believe these results represent a significant achievement and are crucial for the development of next-generation vaccines against influenza and other respiratory pathogens.”

This study is a major immunological breakthrough and paves the way for the development of next-generation influenza vaccines that can provide broad and lasting protection against multiple strains. This achievement could significantly reduce the global burden of influenza and become a vital tool in preventing future epidemics and pandemics.