Badger Vaccination - the science
We support badger vaccination as the best option for Cornwall and have begun our vaccination programme on our North Cornwall nature reserves, as well as the West Cornwall vaccination programme, covering the entire Penwith peninsula. We work with farmers, vets, academics and others as part of the Cornwall TB Eradication Group, a group initiated by Defra.
Badger Vaccination - The Science
- Vaccination of badgers reduces the rate of new infections* in badgers by 76%. Vaccination will not guarantee protection from infection in all individual badgers (this is also true for the human BCG vaccine against TB, which has been used successfully since the 1940s).
- Vaccinating at least one-third of adults in a badger social group reduces new infections* in unvaccinated badger cubs by 79%. This is sometimes known as ‘herd immunity’.
- Each individual badger only needs to be vaccinated once. Vaccination is carried out once per year at each sett for four years. Repeat vaccination is to increase coverage by vaccinating new cubs and adults that might have joined the group over the year.
- Vaccination has no positive or negative effect on badgers that already have TB. Badgers typically live for three to five years, so over a four-year period, vaccination should reduce new cases of TB in badgers whilst infected animals will gradually die off.
- Although the vaccine is live, it is safe and does not lead to shedding of BCG by vaccinated animals; neither does it disrupt badger social groups. Radio tagging studies have also shown that vaccination does not lead to changes in badgers’ ranging behaviour or ‘perturbation’ which happens with a cull as badgers disperse.
- During four years of badger vaccination across a 288km2 area in Pembrokeshire, TB incidence in roadkill badgers declined year on year. The sample size was small, but promisingly, incidence dropped from 19% in year one to 10% in year two, 6.5% in year three and 4% in year four.
- We would expect reduced TB in the badger population to have a knock-on beneficial effect on TB in cattle. If badger vaccination is carried out in more areas, the effects of TB in cattle can be understood better.
- An oral vaccine for badgers is currently in development. This will make vaccinating badgers easier – as and when it is available, programmes can switch to this method.
We are now supporting a farmer-led vaccination programme, with scientists from the Zoological Society of London (ZSL) who are licensed to work on vaccination of badgers. They are also carrying out blood tests to assess the effectiveness of vaccination. We are hoping to roll this out more widely as more farmers become aware of badger vaccination as an alternative to culling.
*measured using diagnostic tests