RVC research highlights pandemic risks of evolving swine flu

Significant diversity in European swine influenza viruses has been found in a new RVC study, raising the need for better pandemic preparation.

Although widespread in pig farming, affecting an estimated 50% of UK production pigs, human cases of swine flu remain rare.

But a 2009 pandemic did show cross into human populations, and humans can transmit flu in the opposite direction, introducing new strains and complicating control efforts.

Virus data

In a collaborative study, one of the most comprehensive antigenic studies of European swine flu to date, virus data from across Europe between 2010 and 2020 was examined.

Immune responses of human populations were also tested in the study, which involved European partners, teams in the US and Taiwan, the APHA and the US Department of Agriculture.

Key findings from the data revealed extensive variation in circulating swine influenza viruses, which raises implications for vaccine updates in pigs and for pandemic preparedness.

The team also found that evolving strains could reduce the effectiveness of existing vaccines, necessitating ongoing antigenic characterisation and monitoring.

Effective vaccines

Amelia Coggon, PhD student at the RVC, said: “Our study has high relevance to pandemic preparedness and swine flu vaccination. By better monitoring how these viruses evolve, we can ensure vaccines used in pigs remain effective, reducing production losses as well as reducing the risk of human infection.

“It also highlights the critical role of international collaboration and ongoing surveillance for zoonotic diseases. Just because we stop looking, it doesn’t mean these viruses disappear.

“Protecting human health begins with investing in animal health, and that means sustained, cross-sector funding – especially for diseases with pandemic potential.”

The full paper in the Journal of Virology is available online.