The Government's single-minded focus on a cull is more a distraction than a solution to tackling this disease. Scientists, who have studied the impacts of a badger cull in England on bovine TB for many years, have stressed it will only make a limited contribution to tackling the disease (1).
Large-scale badger culling trials show an initial worsening of the disease due to perturbation. Over the longer term, there may be a positive impact of a 12-16% reduction of bTB in cattle, but this still leaves at least 84% of the problem. Lord Krebs, who designed a previous trial, concluded that "culling is not a viable policy option" (2).
Since 1998, the Government has invested £30 million in developing bTB vaccines for cattle and badgers. The current status of vaccine development is:
- An injected vaccine called Badger BCG has been available since 2010.
- An oral badger vaccine is being developed, but needs to be tested before potential submission to regulatory bodies.
- A cattle vaccine is a key part of the long term solution to bovine TB. A cattle vaccine is being developed but requires regulatory approval and changes to EU legislation to permit its use – a process that will take around 10 years.
The Wildlife Trusts believe that cattle measures should be at the centre of efforts to tackle bTB, alongside a strategic programme of badger vaccination. In the longer term cattle vaccination will have a vital role to play but it is not yet available. However, a vaccine for badgers is available now and has the potential to help reduce bTB without the negative impacts of perturbation arising from a badger cull.
Vaccinating badgers can significantly reduce the extent of bTB and the potential for transmission to cattle without the disruption of a cull. In a veterinary field study, vaccinating wild badgers resulted in a 74% reduction in the incidence of badgers testing positive to the antibody blood test for TB (3).
In comparison, culling trials have shown that shooting 70% of wild badgers could reduce bTB cases by 12–23% over nine years and may increase cases of bTB on the outskirts of the zones. Even for those who accept a cull of badgers, vaccination will reduce the risk of infection of cattle from the remaining badger population.
Vaccinating badgers can significantly reduce the number of cubs testing positive for bTB. When more than a third of social groups had been vaccinated the risk to unvaccinated cubs was reduced by 79% (4).
The more badgers that are vaccinated the bigger the reservoir of badgers immune to the disease there will be. Ultimately, however, we believe that a cattle vaccine is the sustainable long term solution and we will continue to lobby for Government to negotiate with Europe to make a cattle vaccine a reality.
1. The Duration of the Effects of Repeated Widespread Badger Culling on Cattle Tuberculosis Following the Cessation of Culling. Jenkins et el (2010)
2. Bovine TB: The Scientific Evidence. Independent Scientific Group on Cattle TB (2007)
3. Bacillus Calmette-Guérin vaccination reduces the severity and progression of tuberculosis in badgers. Chambers et el (2011)
4. BCG Vaccination Reduces Risk of Tuberculosis Infection in Vaccinated Badgers and Unvaccinated Badger Cubs. Carter et el(2012)