As the world continues to grapple with evolving infectious diseases, scientists are increasingly turning to pigs in the fight against influenza.
Advances in genetic engineering, immunology, and imaging technologies are positioning pigs as one of the most promising models for developing next generation vaccines and therapies against influenza A virus (IAV).
The threat of a future flu pandemic remains significant. Global population growth, expanding livestock industries, and increased human contact with wildlife have created ideal conditions for new strains of influenza to emerge. Seasonal flu alone already causes substantial illness and death each year, while also inflicting major economic losses on agriculture. Despite decades of research, current vaccines and antiviral drugs offer limited protection. Frequently updated to keep pace with viral mutations, they often fail to prevent transmission.
Writing in Nature Reviews Immunology, a team of international researchers, including experts from The Pirbright Institute, explain the role of pigs as an animal model to study infections in controlled conditions, manipulate immune responses and test new treatments before they are used in humans.
Pig lung anatomy, immune responses and susceptibility to influenza viruses are remarkably similar to humans. Pigs are natural hosts for IAV and the virus behaves in them much as it does in humans. This makes findings from pig studies more likely to translate into effective human treatments.
Technological advances have significantly enhanced the utility of pigs in research. Scientists can now genetically modify pigs to better understand how specific immune cells or proteins influence infection. Breakthroughs in single-cell analysis are allowing scientists to map the pig immune system in unprecedented detail, revealing similarities between pig and human immune responses.
Professor Elma Tchilian, co-author and Head of Mucosal Immunology at Pirbright, says that pigs are an excellent model to study how IAV spreads as droplets or via contaminates surfaces “This makes pigs invaluable for testing interventions designed not just to treat illness but to stop its spread. Pigs are also useful for testing novel vaccines and therapeutic strategies delivered directly to the respiratory tract which may prevent transmission and provide broad protection against different influenza viruses”
Beyond their role as research models, pigs are also central to the global influenza ecosystem. With an estimated 1.5 billion pigs worldwide, they serve as ‘mixing vessels’ for human, avian, and swine influenza strains. This creates opportunities for viruses to exchange genetic material and form new variants with pandemic potential.
Pigs are already used to study other respiratory diseases, including coronaviruses and cystic fibrosis. Their role in medical research continues to expand, highlighted by recent breakthroughs such as experimental pig-to-human organ transplants.
Professor Tchilian and her collaborators believe treatments and vaccines that prove effective in pigs are more likely to succeed in humans compared to those developed using traditional small-animal models. To fully unlock this potential, researchers emphasize the need for greater global collaboration. Standardising experimental methods, sharing resources and building international research networks will be essential to accelerate progress.
As the world seeks better ways to prepare for future pandemics, pigs may offer a crucial bridge between laboratory science and long-lasting defences against influenza.