This approach requires badgers to be individually trapped and injected, annually, for a period of four years. This is a costly and time-consuming process, with the impact of badger vaccination on cattle infection unknown.

The badgers are vaccinated with the BCG (Bacillus Calmette–Guérin) vaccination. This is the same vaccine used in humans, although the dose for badgers is much higher.

Vaccinating badgers will not cure them of bTB. It is a preventative measure.

Badgers typically live four to five years. By vaccinating annually, for four years, the number of badgers vaccinated will increase as the number of infected badgers die off.

Cubs are protected indirectly by reduced contact with infected individuals, otherwise known as the ‘herd immunity’ effect.

Experimental challenge (lab) studies suggest vaccinating a badger with the BCG vaccination can reduce the severity and progression of the disease in an individual animal as well as excretion of the infection, which could lower the likelihood of the animal passing infection on.

Research has shown that:

• Vaccination can reduce the likelihood of badgers developing lesions or excreting TB bacteria.
• Vaccination reduces the rate of new infections (measured using diagnostic tests) in badgers by up to 76%.
• Vaccinating more than one third of the adults in a badger social group reduces new infections in unvaccinated cubs by up to 79%.

Find out more at researchgate.net and journals.plog.org.

There is also no evidence, through laboratory and field studies, to suggest BCG is excreted by vaccinated badgers.

Clinical and safety trials

During clinical and safety trials carried out to get Badger BCG licenced for use, captive badgers were given a large overdose of BCG vaccine.

They were then monitored for 28 weeks. No side effects were noted in response to the overdose of BCG, apart from some small, localised swelling at the injection site. No BCG was cultured from clinical samples taken from vaccinated badgers.

The key conclusion from these studies was that BCG vaccination is safe to badgers and does not result in BCG being excreted into the environment.

While evidence suggests that vaccinating badgers can reduce the infection in badger populations, there are no scientific field trials or experiments which provide a definitive answer about the effects of badger vaccination on cattle.

General licence

In England, trapping and vaccination of badgers requires a licence from Natural England/Defra. Badgers are a protected species, anyone wishing to cage trap and/or vaccinate (and mark) a badger must also attend relevant training.

In 2022, a new and simplified ‘general’ licence was introduced permitting those trained to carry out badger vaccinations to register as an ‘authorised person’, streamlining the administration process and enabling more badgers to be vaccinated.

Natural England conducts inspections to ensure vaccination projects adhere to the licence terms and best practice guidance.

Licence applications also require a prescribing and directing vet, although these can be the same person. Badger BCG is a prescription only medicine and, as such, can only be obtained via a prescription from a practising veterinary surgeon and administered under the direction of a veterinary surgeon.

When and how badgers are vaccinated

The open season for vaccinating badgers runs each year from 1 May to 30 November. The optimum time for trapping is earlier on in the season, when the ground is drier, and their natural food sources are sparser.

Badgers are normally vaccinated while conscious in cage traps placed near signs of badger activity.

Sett surveys are conducted to ascertain badger activity. During the vaccination season, traps are then deployed near setts, runs and latrines. The traps are pre-baited for 7-10 days before being set to catch for two consecutive nights.

Traps are checked early in the morning and captured badgers are health checked, vaccinated (injected) with the BCG vaccine, temporarily marked using a stock spray and released. Vaccinators are then required to record the outcome of each trap set.

Applying temporary marks to the vaccinated badgers avoids any recaptures, on the second night, from being administered with a second dose. All equipment, protective clothing and footwear are cleansed and disinfected, and vehicle wheels and wheel arches sprayed to minimise any risk of transmission of disease between premises.

One cycle of pre-baiting, trapping, and vaccinating lasts between two to three weeks at each location.

Rolling out vaccination

The safety and immunogenicity of the BCG vaccine in European badgers (Meles meles) and Protection of Eurasian badgers (Meles meles) from tuberculosis after intra-muscular vaccination with different doses of BCG are both studies carried out to establish the safety and efficacy in badgers vaccinated with BCG, with no evidence to suggest any negative effects on the badgers’ health or welfare.

Defra continues to explore incentives which can be put in place to facilitate the wider roll out of badger vaccination, with several initiatives having already been introduced.

These include:

• Vaccinating east sussex badgers – a fully funded, farmer led, vaccination project covering over 250km² of the highest risk TB area in East Sussex.
• APHA delivered badger vaccination. Fully funded by Defra and delivered by APHA employed vaccinators, badger vaccination is currently being deployed.

Funding

In 2022, Defra applied a new subsidy to the badger BCG vaccine, cutting the cost of the vaccine by almost 50%, making it more accessible to vaccination groups.

The government has previously provided 50% grant funding to private groups vaccinating badgers in the Edge Area of England through the Badger Edge Vaccination Scheme. This scheme is currently closed to new applications.

Landholders can fund and deliver badger vaccination on their land, providing all licensing requirements are met.

Testing

There is currently only one trap side test available to test badgers for bTB. This is the Brock TB Stat Pak, which requires a few drops of blood. All other tests are currently lab based.

A specially designed cage to physically restrain badgers and a protocol for obtaining a blood sample from the metatarsal pad (foot) for Stat Pak testing are methods currently being trialled by APHA staff in the UK.

This method of safe restraint and blood sampling is the only option for testing live badgers without the need for anaesthesia.

As this approach negates the need for field anaesthesia to obtain a diagnostic sample, it eliminates the risks of associated adverse effects and reduces costs and time before the animal can be released.

These advantages could expand current options for surveillance and disease control interventions in badgers by permitting more efficient trap-side sampling and testing.

However, the testing of equipment and its practical deployment within vaccination areas, as well as reassurances on the sensitivity and specificity of the test are required before wider roll out can be considered.

Faeces can also be used to test badgers for TB, but badger faeces contains intermittent low levels of TB bacteria. This means having to test multiple samples to find evidence of infection and is therefore deemed unreliable in identifying disease.