Vaccination

The logical way forward is to vaccinate the cattle and this is the one area where both sides agree. The reason we don't vaccinate cattle at this time is we couldn't sell them in Europe due to regulations. This was proposed in 1997 by Lord Krebs in his report. We are waiting for a DIVA test to be accepted to differentiate between vaccinated and wild strains. We are supporting the campaign to vaccinate badgers. Badger BCG alone is not the solution to bTB, but it does have an immediate effect with no associated negative impact. The Governments Vaccine Deployment Project is one such undertaking. 

The Badger Vaccine Deployment Project involves trapping and vaccinating badgers (using an intra-muscular injection of BCG)in a 100km2 area near Stroud in Gloucestershire. It dealt with the practicalities of a vaccination programme and in 2011 628 badgers were vaccinated against TB.

The primary aims of vaccinating badgers in the Stroud area are to maintain Fera's capability to vaccinate badgers and to provide training for others who may wish to apply for a license to do so. The Government is considering vaccination along with culling as components of a package of measures to address the TB issue. 

Laboratory and field studies have demonstrated that vaccination of badgers by injection with BCG significantly reduces the progression, severity, and excretion of TB infection.

Chambers et al (2010) showed the BCG vaccination of free-living badgers reduced the incidence of positive serological test results by 73.8%.

References

  1. http://www.brockvaccination.co.uk/why-vaccinate-badgers/
  2. http://www.shropshirewildlifetrust.org.uk/Badgers+and+bovine+TB/Badger+vaccination

 

Government Chief Scientific Advisor explains Badger and Cattle vaccination 

Professor Ian Boyd is Chief Scientific Adviser at the Department of Environment, Food and Rural Affairs.

Vaccination will be an important tool to help control bovine TB in the future. But the evidence suggests it will not work on its own – and where both cattle and badgers are concerned, a realistic programme remains a number of years away.

Vaccination and Badgers

Most voices in the debate, including the NFU, support the use of badger vaccination in areas on the edge of the disease spread to help stop bTB spreading further. Farmers are getting involved in badger vaccination projects in these areas because they recognise that vaccination could have a role to play in stopping disease spread.

The Government has also set up the Badger Edge Vaccination Scheme (BEVS) to support badger vaccination projects in areas on the edge of the disease spread that are thought to be most at risk of the disease spreading from the endemic areas of the South West and West Midlands. However, in December 2015 the Government announced that all badger vaccination projects in England were being suspended due to a global shortage of the BCG vaccine. In July 2017 Farming Minister George Eustice announced that the BEVS would restart in summer 2018 and applications for grants from groups interested in running projects would be accepted from late 2017.

The only vaccine currently available for use on badgers is in an injectable form – and that presents problems. You need to cage-trap the badgers to vaccinate them and you have to it annually for a period of at least five years. The process is costly and needs to be carried out by people who have been on accredited courses. Every trap has to be visited early in the morning, every day.

The Welsh Assembly Government is carrying out a five-year badger vaccination programme in the Pembrokeshire hotspot area. In December 2015 the Deputy Minister for Farming and Food, Rebecca Evans, announced that the badger vaccination project in Wales was being suspended due to a global shortage of the BCG vaccine.

In May 2015, the report on the third year of the programme was published and showed that 1,316 badgers had been vaccinated at a total cost of £929,540, or approximately £706 per badger. During the second year of the programme, 1,352 badgers were vaccinated at a total cost of £926,784, or approximately £685 per badger. The first year of the programme saw 1,424 badgers vaccinated at a total cost of around £943,000, or approximately £662 per badger.

There are also question marks over the efficacy of the vaccine. It will not cure a sick badger, one which is already infected with TB. The science suggests the vaccine is most effective in very young animals, and less so in older subjects Read the full report here 

Young badgers spend their early weeks in the sett, making it impossible to trap and vaccinate them and putting them at risk of infection before they emerge. There is also no evidence as yet which shows that vaccinating a proportion of the badger population actually results in a reduced risk to cattle.

An oral bait vaccine is likely to offer the most successful route forwards but this option is still some years away from becoming a part of any badger control plan because there is no licensed or proven oral vaccine currently available. The Government's TB eradication strategy for England suggests 2019 as the earliest when an oral badger TB vaccine may be deployed, subject to research breakthrough and authorisation.

Vaccination and cows

There are calls for cows to be vaccinated against bTB. However, there is no legal vaccine available.

Currently, the only option is the BCG vaccine (Mycobacterium bovis Bacille Calmette-Guérin). The problem is that at present it is impossible to distinguish between a BCG-vaccinated and TB-infected cow, and for this reason, it is currently illegal under EU law to vaccinate cattle with the BCG jab. Work is underway to devise a DIVA test that can Differentiate between Infected and Vaccinated Animals, but even when this has been fully developed, it will need to go through EU and international approval. The upshot is that most estimates say it will be ten years before vaccinating cattle is a realistic possibility.

On top of that, there's evidence to suggest that the BCG vaccine and DIVA test will not eradicate bovine TB on their own. A recent scientific study (see the full report here)  concluded that the efficacy of the BCG vaccine in cattle was between 56% and 68%.

We know the BCG vaccination reduces the progression, severity, and excretion of TB, resulting in reduced transmission between animals, but it is not perfect, and for any vaccine to eradicate a disease it is necessary to ensure that 80% of the target population are immunised. The current BCG vaccine does not shape up.

Scientists have said that vaccination has to be used in combination with other measures, which must include dealing with the disease in badgers. You can read more about bovine TB and cattle vaccination on the Defra website.

Prof Rosie Woodroffe takes an alternative view: 

Prof Woodroffe, who was a key member of the team that spent 10 years and £50m testing badger culling before concluding that culling could "make no meaningful contribution" to reducing bovine tuberculosis (TB) claims Vaccinating badgers would cost less than culling them.

Prof Woodroffe quotes from an analysis of the Governments own data. Woodroffe's analysis used the government's own cost estimates of badger vaccination – £2,250 per square kilometre per year – and the proposed culling – £1,000/sq km/year. When government estimates of policing costs for the cull – £1,429/sq km/year – are added, vaccination becomes the cheaper option.

"Vaccination does not prompt protest, so it is cheaper to implement than culling," said Prof Woodroffe. "There is a good reason to expect badger vaccination to reduce transmission to cattle," She continued "Vaccination is often dismissed as a management option because it has no direct effect on infected badgers. But this is based on a misinterpretation of the available evidence: culling does not prompt a rapid reduction in the numbers of infected badgers."

"The general public does not object to vaccination and there is likely to be no protest whatsoever," said Woodroffe, adding that the Welsh assembly has chosen badger vaccination over culling as its TB control policy and seen no protests. Badger vaccination trials are also being undertaken in England by the Gloucestershire Wildlife Trust and the National Trust in Devon.

Woodroffe said her analysis did not include the additional costs incurred by culling as a result of having to perform expensive surveys to measure badger populations. The cull must kill at least 70% of badgers to ensure escaping animals do not spread TB further but must not kill them all, as local extinctions are illegal. "We know vaccinating badgers reduces transmission of bovine TB to other badgers, so there is good reason to expect it also to reduce transmission to cattle," she said. "Vaccination is also expected to reduce the proportion of infected badgers, rather than increasing it as culling does, so it may have greater long-term prospects for TB eradication." 

The government's cost-benefit analysis predicts a 16% reduction in TB in cattle after nine years as a result of culling but found the cost of the cull exceeded the cost of the TB infections avoided. The scientist who set up the 10-year trials, Lord John Krebs, has described the badger cull as "mindless."

 

 

 

 

 

 

 

 

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