Questions raised over EIV vaccine role
A state-of-the-art review published in this month's Equine Veterinary Journal has raised questions about the role of equine flu vaccination in limiting the spread of infection and reducing the severity of clinical signs.
Lead author Dr Janet Daly, a virologist from the University of Nottingham's School of Veterinary Medicine, investigates how mathematical modelling could help us bring equine influenza (EIV) under control and protect horses more effectively.
The review, entitled "What can mathematical models bring to the control of equine influenza?", collates findings from a number of studies over the past 10 years.
Dr Daly concludes that while vaccination does reduce the occurrence and limit the severity of outbreaks, the protection given by equine flu vaccines is not as straightforward as we may have thought.
According to the review, EIV has the ability to mutate, thereby reducing the effectiveness of older vaccines. According to the review, none of the vaccines currently on sale in the UK contain the most recently recommended strains of the virus.
Although EIV is rarely fatal, it is highly contagious and can cause serious disruptions to training and competition schedules, resulting in large revenue losses in the equine industry.
Dr Daly said: "This study will help further our understanding of how to better protect horses against the effects of equine influenza.
"Mathematical modellers have to make some assumptions in developing models, but models are informed by and tested against real data. As a virologist, I find the questions about the data they need to generate their models challenge me to think differently about the disease."
Meanwhile, the BEVA is working with key parties to encourage further education and surveillance of EIV and establish revised guidelines to facilitate and reduce costs of approvals for vaccine strain updates.
The BSAVA has opened submissions for the BSAVA Clinical Research Abstracts 2026.
