Bovine tuberculosis (TB) is the greatest animal health challenge faced by Britain’s farmers, and simultaneously Britain’s greatest wildlife controversy. TB is primarily a cattle disease, but badgers can become infected, and transmit the infection to cattle, and so badger culling has been part of England’s TB policy for decades. The badger culls implemented in the past few years have been by far the most draconian, however: in autumn 2019, an area of England roughly the size of Israel was covered by badger culling licences, with the National Farmers’ Union envisioning, within the next couple of years, an unbroken cull zone from Land’s End to the Peak District.
It was a surprise, then, when on 5thMarch the government announced a plan to gradually replace badger culling with badger vaccination. This announcement was part of the government’s long-awaited response to an independent review of TB policy, which was completed in 2018 and discussed here previously. Most mainstream news outlets heralded the end of the unpopular badger cull, but the National Farmers’ Union (a powerful voice in these matters) emphasised that the new policy did not, in fact, mean an end to culling. So, what does the new policy really mean?
In the long term, the new policy should bring good news. Both farmers and conservationists look forward to a far-off day when TB is eradicated from British farmland. Then, neither cattle nor badgers will need to be slaughtered to control the disease. That day is still decades away, but the actions outlined in this policy should help to bring it closer. Reassuringly, most of the planned activities focus on managing TB in cattle, including trials of cattle vaccination and improvements to cattle testing – this is appropriate when an estimated 94% of TB-affected cattle herds are infected by other cattle.
For the estimated 6% of herds infected by badgers, a move from badger culling to vaccination should also be good news. Badger vaccination offers a greater chance of TB eradication; culling cannot eradicate TB because it changes badger behaviour in ways which encourage TB spread, so badger numbers go down but TB doesn’t go away. In contrast, vaccination works with badgers’ natural tendency to self-isolate, and could potentially lead to eradication if implemented over several years and in combination with cattle controls. Good news too for taxpayers, because vaccination offers a cheaper approach than culling. And good news, of course, for badgers, which will have a chance to live and contribute to England’s depauperate ecological communities.
A widespread roll-out of badger vaccination may be welcome, but it can’t happen immediately, for three reasons. First, cull licences are issued for 4-5 years, because culling has to be repeated annually for at least four years for it to reduce cattle TB. Of the land culled in 2019, 86% is covered by such multi-year licences which commit the licensees to cull again in 2020. Withdrawing these licences would undoubtedly trigger legal action, which the government would probably lose.
Second, training enough vaccinators to cover this huge area will take time. Persuading a wild animal to go into a cage and then let you stick a needle into it (safely and humanely for all concerned) is not something you can learn without practical training in the field. Training needs trainers, as well as badgers for the trainees to practice vaccinating, and right now there are not enough of either in the few places where vaccination is licensed. Recognising this, the government plans to support badger vaccination in some areas of high TB risk which have not been culled, partly to provide training grounds for vaccinators.
Third, many farmers are either unaware that badger vaccination is available, or assume that it is ineffective. There is much work to do, therefore, to share knowledge about badger vaccination with farmers and farm vets, to build trust and understanding. The government’s new policy recognises these limitations on the roll-out of badger vaccination, and proposes ways to address them.
So far, so good. But phasing in badger vaccination does not mean that badger culling will be completely phased out. While vaccinators are being trained, and information shared with farmers, new cull licences will continue to be issued. This is disappointing, and not just because it will kill thousands of badgers. Worryingly, the government justifies it by a mistaken view that, because culling reduces badger numbers and can (under certain circumstances) reduce cattle TB, it also reduces TB in badgers. The government states that “Badger vaccination is likely to be better and more cost-effectively deployed once the badger population has been reduced, to enable a healthy population to regenerate.” This sentence is so riddled with errors it’s hard to know where to begin. Badger vaccination will be lesseffective in recently-culled areas, not more. Culling increases the proportion of infected badgers, undermining any subsequent vaccination, which works by protecting individuals which have not yet become infected. Culling also makes badgers trap-shy, and hence harder to vaccinate. It’s likely, therefore, that a “healthy population” of badgers could be achieved more rapidly by vaccination alone than by culling followed by vaccination. It’s also not clear that vaccination would be much cheaper where badger density is reduced: the main cost of vaccination is the effort of deploying traps, and traps will need to cover the same area, however few badgers there may be. For these reasons, issuing new cull licences delays and undermines subsequent vaccination, as well as being costly and environmentally damaging. There is a mindset that “doing nothing is not an option” but, if vaccination is a promising tool for TB eradication, it seems strange to issue licences for culls that will undermine it.
Even more worrying is the government’s plan that “culling would remain an option where epidemiological assessment indicates that it is needed”. This is worrying, because epidemiological assessments (which are conductedby local vets asked to make a judgement about the source of infection) tend to attribute a high proportion of cattle TB infections to badgers (e.g, 77% in Derbyshire) even though scientific evidence (including analysis of data from the Randomised Badger Culling Trial, and more recent studies of bacterial genome sequences) shows that most herds are infected by other cattle. There is a risk, therefore, that future badger culls might still be licensed on the basis of dodgy assumptions. The National Farmers’ Union statement suggests that they are hoping to maintain widespread culling by this route.
Government policies are often compared with supertankers: lumbering and difficult to turn. In this case, the captain has ordered a change of direction, but it is not yet clear how far or how quickly the ship will respond. For a successful change of direction, it will be essential to collect and openly share data on the implementation and consequences of badger vaccination, so that scientists, farmers, vets, and policymakers can reach a shared understanding of its merits.