Bovine Tuberculosis: Vaccination
(asked on 29th November 2021) - View Source
Question to the Department for Environment, Food and Rural Affairs:
To ask the Secretary of State for Environment, Food and Rural Affairs, what recent assessment his Department has made of the potential merits of widespread vaccination of the UK’s badger population for the purpose of reducing the spread of bovine tuberculosis; what evidence his Department has that vaccination will be effective in protecting livestock on farms in England; and whether his Department will make provisions to retain culling in areas where vaccination does not prove effective.
Evidence indicates that vaccination reduces disease burden in the badger population, with field trials showing that vaccinated badgers were at least 54% (and up to 76%) less likely to test positive for TB. The same field trial found that when more than a third of the social group was vaccinated, infection risk to unvaccinated cubs reduced by 79% (Carter et al 2012 [1]).
Both modelling in a post-cull environment in England (Smith GC & Budgey R, 2021 [2]), and evidence from Ireland (Martin SW, et al. 2020 [3]), suggests that vaccination following culling should help maintain reductions in cattle TB incidence. In a trial of badger vaccination in Ireland, vaccination was found to be as effective as long-term continuous culling in lowering cattle TB incidence in four of the seven counties studied, which led to a policy change to gradually replace culling with vaccination.
Logically, as badgers cause a proportion of cattle breakdowns and badger vaccination has been proven to reduce the disease burden in badgers, vaccination is expected to result in a reduction in cattle TB incidence where badgers are infecting cattle. However, there has been no trial in England to assess the magnitude or timing of these effects. Accordingly, we are developing a surveillance and monitoring system that will allow us to monitor levels of disease in wildlife and cattle. This will enable government and industry to be more agile in tackling the disease.
Badger culling would remain an option where epidemiological assessment indicates that it is needed.
[1] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0049833