Scientists at the Pirbright Institute and the University of Oxford have taken a significant step towards developing a universal human influenza vaccine by studying pigs.
Vaccines are an important defence against flu, but are designed to target specific strains of the virus, which change rapidly each year. As new variant strains emerge, the protection offered by these vaccines quickly diminishes, necessitating annual updates and making it harder to combat potential pandemic threats.
In the new study, published in NPJ Vaccines, the researchers have generated new evidence supporting the development of a universal influenza vaccine that could protect against multiple strains.
Rather than focusing solely on antibodies, the approach aims to activate T-cells, which can recognise and respond to a variety of flu viruses. The team also explored the use of aerosol vaccines, delivered directly to the respiratory tract.
The researchers immunised pigs pre-exposed to pH1N1 using aerosolised viral vectored vaccines (ChAdOx2 and MVA) that express the influenza matrix protein (M1) and nucleoprotein (NP). The results showed T-cell responses induced through aerosol immunisation can offer significant protection.
The pig model is particularly valuable in influenza research, as pigs are large natural hosts for influenza A viruses and share many physiological and immunological similarities with humans.
Professor Elma Tchlian, head of Pirbright’s Mucosal Immunology Group said: “This study shows the importance of targeting the respiratory tract through aerosol administration to induce local immunity and prevent severe disease. This approach has significant implications for both human and veterinary medicine and highlights the potential of respiratory vaccines for influenza and other respiratory pathogens.”
Professor Dame Sarah Gilbert, Professor of Vaccinology at the Pandemic Sciences Institute, University of Oxford, said: “We believe that these results are a significant advance and highly relevant to the development of next generation vaccines for influenza and other respiratory pathogens.”
The researchers believe the study represents a major immunological advance and paves the way for next-generation influenza vaccines that could offer broad and durable protection across multiple strains.