Equine Influenza Vaccine Update
28th November 2022
We are delighted to confirm that the supply of equine influenza (EI) vaccines within the UK has now returned to normal and suitable products are available from all three manufacturers i.e. Boehringer Ingelheim, MSD and Zoetis,
BEF’s member bodies are to be commended for responding rapidly and responsibly to the EI vaccine shortage as it emerged in late August and early September. BEF-EIDAG and BEVA are now hopeful that we can rapidly respond to again encourage horse owners and riders to reinstate what we consider are the most effective vaccination protocols.
Reverting booster intervals from 15 to 12 months
For those member bodies which permitted extension of the 12-month booster requirement to up to 15 months, we recommend that this provision is discontinued after 31 December 2022. In this way, any horse owner who was made aware of and adopted the extension in early September, will be able to have their horse re-vaccinated before the end of 2022. It is also important to emphasise the extension first applied in September 2022 carried the condition that the 2023 vaccine booster date was to be no more than 24 months from the 2021 due date (so that two boosters were given within a two-year period). Any horse owner who took up the ’two-in-two’ option should have been informed of this by the vet who has or will administer a vaccine before the end of December 2022 and the correct booster due date in 2023 should be entered in the horse’s passport and therefore we hope any future confusion may be minimised.
Reverting to or adopting booster intervals within 6 months
This Autumn, British Dressage, British Eventing, British Horseball and British Carriage Driving all temporarily waived their requirements for vaccination within 6 months of competition (in line with the FEI, who did the same) while British Showjumping relaxed their recommendation for a vaccine within 6 months of competition. We advise that the requirement for vaccination within 6 months of competition is re-instated on 1 January 2023. For information on the benefits of 6 monthly vaccination, we recommend reading an editorial that has been produced for the Equine Veterinary Journal and is openly available at:
In this article Drs Vicky Colgate and Richard Newton, from Cambridge University Vet School, discuss the scientific evidence for this proposal in detail and highlight the following key points:
Influenza has high epidemic potential: the UK-wide problems which occurred in two phases in 2019 affected many equestrian premises and led to the cancellation of numerous equine gatherings. Recently the UK again experienced a notable spike in EI reports mainly relating to the introduction of unvaccinated new horses to premises.
Higher antibody levels, stimulated by regular vaccination, are associated with reduced risk of EI virus infection and clinical disease. Antibodies drop off in proportion to the time since last vaccination, therefore reducing intervals between boosters optimises the antibody levels and the amount of protection afforded across the horse population. This also provides better protection of poorly responding horses – a phenomenon known as herd immunity.
Evidence from observed clinical outbreaks in UK and Ireland repeatedly highlight the potential for 12-monthly boosters to leave a vulnerable immunity gap at both the individual animal and population level. Mathematical modelling strongly supports this conclusion. Although much of this work arises from racehorses as the most closely monitored group of vaccinated horses, this phenomenon is also seen in other vaccinated equine populations.
Equestrian sports greatly facilitate both direct and indirect contact between groups of horses which then return home to geographically disparate areas. These contact networks can be formed over hundreds of miles and can allow infectious diseases to rapidly and widely propagate internationally and across the UK.
Gathering horses at competitions caries an inherent risk of spreading infectious disease. Organisers and competitors have a social obligation to act in line with current best evidence to mitigate that risk and to ensure we maintain our social licence to pursue equestrian sport.
We thank you for your assistance in this matter and would be very happy to provide more information on the benefits of 6 monthly vaccines to you or your board members if this is helpful.