Research reports
related to the control of bovine tuberculosis in badgers have been
made public today.
Defra has made public supporting data behind the successful
licensing of the first tuberculosis vaccine for badgers (Badger
BCG), which was licensed by the Veterinary Medicines Directorate
in March this year. The studies were carried out by the Veterinary
Laboratories Agency (VLA) and the Food and Environment Research
Agency (Fera).
The laboratory studies with captive badgers demonstrated that the
vaccination of badgers by injection with BCG significantly reduces
the progression, severity and excretion of Mycobacterium
bovis infection.
A key finding of the field study, conducted over four years in a
naturally infected population of more than 800 wild badgers in
Gloucestershire, was that vaccination resulted in a 74 per cent
reduction in the proportion of wild badgers testing positive to
the antibody blood test for TB in badgers.
The blood test is not an absolute indicator of protection from
disease, so the field results cannot tell us the degree of vaccine
efficacy. While the findings indicate a clear effect of
vaccination on badger disease, data from the laboratory and field
studies do not lend themselves to giving a definitive figure for
BadgerBCG vaccine efficacy. Nor do they provide information on the
effect of badger vaccination in reducing TB incidence in cattle.
A scientific paper summarising the results of the injectable BCG
badger vaccine research has been accepted for publication by the
scientific journal Proceedings of the Royal Society B (Biological
Sciences) and will be published shortly.
Professor Glyn Hewinson, Head of the TB Research Group at the
VLA, and Professor Robbie McDonald, Head of the Wildlife and
Emerging Diseases Programme at Fera, said:
“VLA and Fera are very proud to have conducted the programme of
work on BadgerBCG and that a vaccine is now available for use in
the field as one of the tools for tackling bovine TB. In making
the data available today, we hope that people will be able to see
for themselves the detailed research that went into the
development of the vaccine and understand the opportunities and
challenges of using vaccination.”
Defra is also publishing today the results of new computer
modelling by the Food and Environment Research Agency (Fera),
which has examined different strategies for controlling TB in
badgers, including both culling and vaccination.
The results of the modelling were consistent with the conclusions
of the Randomised Badger Culling Trial indicating that there were
both positive and negative effects of culling. The modelling shows
that badger vaccination could make a positive contribution to
disease control in its own right and was consistently positive
when used in combination with culling in a ring vaccination
strategy.
The results of the modelling were that:
a) A combined strategy of vaccination in a ring around a culling
area was more successful than the cull-only strategy, which in
turn was more successful than the vaccination-only strategy, both
in reducing the number of TB infected badgers and cattle herd
breakdowns. Ring vaccination partly mitigated the detrimental
effects of culling. However, the combined strategy requires about
twice as much effort than either single approach done in
isolation.
b) Culling of badgers should continue for at least four years to
realise a clear benefit. However, low rates of land access for
culling, or low culling efficiency, or the early cessation of a
culling strategy was likely to lead to an overall increase in
cattle herd breakdowns (whilst this is not the case for
vaccination).
Notes for Editors
1. The results of the research has been published on the Defra
website and is available at:
http://ww2.defra.gov.uk/food-farm/animals/diseases/tb/
2. The Veterinary Medicines Directorate (VMD) issued an
authorisation for BadgerBCG vaccine on 24 March 2010. VLA is the
market authorisation holder and the vaccine is manufactured by the
Statens Serum Institut in Denmark.
3. VLA is an executive agency of the Department of Environment,
Food and Rural Affairs (Defra). It is a regional network of 16
veterinary laboratories including a central facility near
Weybridge in Surrey.
4. VLA provides a wide range of applied research and consultancy
on livestock diseases and surveillance of new and emerging
diseases for the Government and animal health industry. It is also
a national and international reference laboratory for many farm
animal diseases including avian influenza, bovine tuberculosis,
classical swine fever and TSEs.
5. The Food and Environment Research Agency (Fera) is an
executive agency of Defra. Its remit is to provide robust
evidence, rigorous analysis and expert professional advice to
government, international organisations and the private sector, in
order to support and develop a sustainable and secure food chain,
a healthy natural environment, and to protect the global community
from biological and chemical risks.
6. Fera has the largest group of wildlife management specialists
in the UK. This along with extensive facilities and resources has
positioned their scientists as leaders in wildlife management and
disease control. Fera is responsible for the coordination of the
Badger Vaccine Deployment Project.
7. The Coalition has committed to publishing a balanced and
comprehensive bovine TB eradication programme early in 2011. In
preparation for that a public consultation on our proposed
approach to badger control is currently underway. The consultation
document is available on the Defra website and closes on 8 December.
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Contacts:
Defra Press Office
Phone: 020 7238 6600
NDS.DEFRA@coi.gsi.gov.uk
Tom Briggs
Phone: 020 7238 6140
tom.briggs@defra.gsi.gov.uk