Vaccine ready to counter emerging bluetongue BTV-8 threat

Farmers looking to protect their livestock against the BTV-8 bluetongue variant have another tool at their disposal, with the Syvazul BTV-8 vaccine now available for use in England, Scotland and Wales.

The vast majority of the 337 cases of bluetongue seen in Great Britain since 1 July 2025 have been of the BTV-3 variant.

See also: How timely bluetongue vaccine prevents dummy calves

However, there have been seven cases where both BTV-3 and BTV-8 have been found together, and another four cases of BTV-8 in isolation – the most recent being a cow in East Sussex, tested following a late-term abortion.

The Syvazul BTV vaccine was originally approved during the 2008 bluetongue outbreak in the UK, and can include serotypes 1, 4 and 8.

A spokesman for UK distributor Virbac said: “But we have opted to only include BTV-8 at this time, therefore have called the product Syvazul BTV-8.

“It has remained licensed since 2008, but has been unavailable in the UK because we have not had the cases or requirement for vaccination until now.

“The vaccine can be used during pregnancy and lactation and carries a zero-day withdrawal period, supporting uninterrupted farm productivity.”

Dutch manufacturer Boehringer Ingelheim also has a licence for a BTV-8 vaccine using its BTVPUR platform. Supplies are expected to be with wholesalers “imminently”.

With midge activity expected to accelerate in the warmer weather, vaccination remains the most effective tool for reducing clinical signs and lowering viral load within a herd or flock, say vaccine manufacturers.