Poultry farmers are appealing to the government to let them vaccinate their flocks against the “devastating” bird flu virus spreading across the UK.

Vaccinating poultry against avian influenza is currently not allowed in the UK. The government says that strong biosecurity measures and culling are the most effective ways of fighting it. Meanwhile, there are concerns that poultry vaccinations might be linked to the virus evolving.

Overall levels of the virus have not yet reached the peak of recent years.

But one farmer, who has previously lost 30% of his flock because of bird flu, told the BBC that, without a vaccine, it was only a matter of time before “it all kicks off again”.

A bird flu prevention zone enforcing strict hygiene standards around domesticated birds has been declared for England, Wales and Scotland amid a rising number of cases of highly pathogenic avian influenza (HPAI).

The risk to humans remains low, with chicken and eggs safe to eat if properly cooked, according to the Department for Environment, Food and Rural Affairs (Defra).

Defra has set up a cross-government and poultry industry taskforce that is looking at the potential use of vaccines, and is due to publish its report later this year. But poultry farmers say things are moving too slowly.

Essex turkey farmer Paul Kelly, whose business was hit hard in the worst avian flu outbreak from 2021 to 2023, told the BBC that “the foot has been taken off the gas” when it comes to making poultry vaccines available to UK farmers.

“This is poor planning as we need to be ready for another huge outbreak as opposed to reacting to another outbreak and being behind the curve on rolling out vaccination,” he said.

“Avian influenza is so highly pathogenic that if a farmer gets it [in his flock][ it is devastating.”

There have so far been 25 farm outbreaks of bird flu since the annual winter recording season began in October.

In comparison, between October 2021 and January 2022, during the UK’s worst outbreak, there had been more than 70 cases in poultry or other captive birds.

But Gary Ford, of the British Free Range Egg Producers Association, said that there was still “panic, concern and fear out there” among farmers over the virus spreading.

He added that the organisation was a “huge supporter” of vaccination for poultry but recognised there were challenges, including the cost to farmers and the impact on trade with other countries that prohibit imports from producers that vaccinate.

Meanwhile, there have also been some scientific questions raised about bird flu vaccinations.

Recent work by researchers from the UK’s Royal Veterinary College and institutions in China found possible evidence that they may be linked to changes in how the virus evolves.

They carried out genetic analysis of avian flu samples collected from wild birds and farmed poultry between 1996 and 2023.

While they found that infections occurred more often in unvaccinated birds, they also found that in countries with high vaccination rates, there was a higher rate of change in the virus itself.

They said such evolution could, in theory, lead to vaccines needing to be updated frequently to remain effective and to the virus spilling over into unvaccinated populations. They acknowledged that more research was needed to establish whether there was a direct causal link between vaccination and virus evolution.

Earlier this week, the government agency that deals with infectious diseases, UKHSA, confirmed a case of the H5N1 avian influenza virus in a farm worker in the West Midlands region.

It said bird-to-human transmission of avian influenza was rare and that the risk to the wider public continues to be very low.

Farmers in Shropshire, North Yorkshire, East Riding of Yorkshire, City of Kingston Upon Hull, Lincolnshire, Norfolk and Suffolk have to keep their birds caged under mandatory housing rules put in place to manage the spread.

Biosecurity restrictions are also in place across England, Wales and Scotland as part of an Avian Influenza Prevention Zone.

The National Farmers’ Union said it was “essential that Defra refocuses efforts” on coming up with a workable avian influenza vaccination plan for the UK.

The government currently only allows licensed zoos to vaccinate captive birds against HPAI.

It said it would continue to invest in research and that any future decisions on the use of emergency or preventive vaccination would be based on the latest scientific evidence and veterinary advice.