Bluetongue - the myths, rumours and the real truth

Bluetongue vaccination has slowed down as farmers grow increasingly sceptical about the vaccine. Jack Davies looks at the issue.

The farmyard rumour mill has been in overdrive this summer, spreading word across the industry that the bluetongue vaccine can cause all manner of side effects and animal health problems.

As rumours have taken hold, vaccination has almost ground to a halt in parts of Wales and Northern England, potentially threatening the disease status of livestock around the UK.

With tales of vaccinated animals dropping dead, becoming sterile or aborting, farmers are increasingly wary of vaccinating, especially during tupping season.

One sheep and beef farmer from the Welsh border told Farmers Guardian he decided not to vaccinate when several farmers at sales and his local auction market told him about infertility and abortion claims.

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Anecdote

One anecdote included a farmer who had vaccinated but, come tupping, had counted only 10 ewes with raddle marks.

The farmer said: “Our vet advised us to do it. He said ‘Don’t come running to me when you get bluetongue’ but we said ‘Who do we run to if our cows abort?’”

He said his vet was charging over 70p per dose, which he thought too expensive, especially when farmers in some European countries were getting it for free.

“If he sells 1,000 doses he’s quids in,” he said. To consider vaccinating, he said he would want assurances that cows would not abort, otherwise he would not be willing to take the risk.

These rumours have created a climate of fear among farmers and with no evidence of active disease currently circulating in the UK, many feel it is simply not worth taking the risk.

Theories concerning fertility and abortion have been tested repeatedly by the Veterinary Laboratories Agency (VLA) over the summer and it is yet to identify any problems caused by the vaccine.

Similar tests in Europe where vaccination has been in place for a number of years have also disproved the rumours.

“I have seen no evidence whatsoever of the vaccine causing infertility,” says Dr Chris Oura, a bluetongue expert at the Institute of Animal Health. “In fact,

Portugese authorities have studied fertility year-on-year during their bluetongue vaccination programmes and they have found no evidence of that happening.

Other reasons

“If you do have a problem you need to investigate it. There have been a lot of investigations by the VLA and in almost every case they have found another reason behind these problems identifying diseases the farmer may not have picked up on otherwise.”

The same is true for some ofthe other rumours currently circulating, including the idea that vaccination can cause a dramatic drop in milk production – a symptom of the disease rather than the vaccine.

Such problems can often be caused by a variety of factors and while it may be tempting to jump to conclusions, the persistent rumours are gradually taking momentum away from the vaccination programme.

“It is alarming to think that ‘farmyard science’ is being used to inform people’s decisions whether to vaccinate or not,” says Alastair Johnson, senior livestock advisor at the NFU. “If there is a rumour out there it has been disproved time and time again when it has been investigated and people have looked into the issue.”

Farmers also face logistical issues in getting animals vaccinated as well as suffering from complacency.

One dairy farmer from the North West says he will not be vaccinating until next spring when the warmer weather would mean bluetongue was more of a threat.

“Our heifers are away from home now anyway so we’ve decided to wait and vaccinate the whole herd when we do our usual vaccinations in the spring time,” he says.

Nicky Paull, president of the British Veterinary Association (BVA), says the vaccination programme has become a victim of its own success, with high uptake in the south of England damping down the spread of disease, allowing complacency to slip in.

“Concerns about side effects are just one part of the problem,” she says. “There were the same concerns in Cornwall when we

introduced the vaccine into our practice but the drive to vaccinate and tackle the disease was still there so we saw a high uptake from our farmers.

Visible threat

“If we had seen circulating virus this year then a lot of farmers who were thinking about not vaccinating would have done so, because they would have seen a visible threat.

“All summer long we have been saying ‘look at what happened in Northern Europe last year and thank god it hasn’t happened here’, but you can only repeat that message so many times before people get bored of it.”

The reaction among farmers in Wales and the North of England is in stark contrast to those at the heart of last year’s outbreak, where an uptake of around 90 per cent was hailed as a major success for the industry.

Mr Johnson says: “In terms of those who have been affected by the virus in the South and the South West, the vaccine couldn’t come quickly enough.

“They knew there was an immediate risk and they moved very quickly indeed to protect their herds and flocks and we have seen a very high uptake in those areas.

“When it comes to May next year I am sure they will be looking to give booster injections, because they have seen what the disease can do and they want to stop it.”

Despite the success of vaccination, there is still some way to go before farmers are free from risk with the virus spreading like wildfire in France and other northern European countries.

“We are not out of the woods just yet,” says Dr Oura. “But it looks like we have been very successful so far, due to the very high level uptake in the high risk areas.

“There may still be disease in wild animal populations and there is a possibility disease is circulating sub-clinically at the moment. There is also the threat from mainland Europe, we only have to look at the spread in France where they have struggled to contain the disease to understand the constant risk livestock in the UK is at.

Import risk

“We have seen animals imported from the continent bringing the disease over so we know this can happen and we are at risk from it.”

The situation in Europe is a major worry, with two strains of disease rampant in France the issue of importing infected animals could become even more critical.

Mr Johnson says: “Imports from those areas now carry a risk of importing not only BTV8 but BTV1 as well and we are not equipped to deal with that strain yet in the UK.

“We can’t put a blanket ban on imports because then we wouldn’t have a leg to stand on when it comes to our exports. But farmers themselves should have an individual ban on importing stock onto their own farm from bluetongue zones on the continent.

“If they must import, then get them blood tested and be as certain as you can that they are free from the virus because imports are the easiest way to bring the disease back.”

Scientists are adamant that the UK is still at risk – not only from continental disease but also the possibility of disease overwintering in wild or unvaccinated stock in the UK.

Encouraging vaccination next year will be an uphill battle for the industry and, with no signs of disease this year, many farmers will be sceptical about paying for more vaccine to combat what many see as an invisible threat.

“It is going to be hard for the veterinary profession next year,” says Ms Paull. “The things happening in other countries may at times appear far away and people don’t appreciate the level of risk.

“Vets will have to do all they can to help farmers with this. What we should be saying is ‘haven’t we done well, but let’s maintain the impetus into next year’ because we do need to stay on top of this disease or it will come back.”

With vaccine available much earlier next year, logistical issues that discouraged many farmers this year should be overcome and they will be able to vaccinate before turning stock out.

The availability of vaccine in 2009 is currently the subject of debate at Defra and following this year’s disappointing uptake in some areas the industry will be thinking about new ways to encourage higher levels of vaccination next year.

“To get the amount of vaccine as we did into animals as quickly as possible this year, we had to make it a voluntary strategy and that was the right way to go,” says Mr Johnson.

“Whether that mechanism will be the same for 2009 we don’t know. Decisions will need to be made on the most effective course of action is to make sure we get booster jabs out quickly and ensure that those who haven’t already done so vaccinate their stock ready for summer 2009.”

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