Bovine TB: The Badger Vaccine

Transcription

1 Bovine TB: The Badger Vaccine Deployment Project

2 Introduction Defra is funding a project to vaccinate badgers against bovine TB in six areas of England with high bovine TB incidence in cattle, starting in summer 2010: The Badger Vaccine Deployment Project. This is part of the Bovine TB Vaccines Programme which is dedicated to developing TB vaccines for badgers and cattle. Vaccination of either cattle and/or wildlife is an important long-term policy option for reducing the risk of bovine TB in Great Britain and, as such, a substantial part of the Defra TB research programme focuses on this. An injectable BCG badger vaccine will be the first product available from the research programme. It is anticipated that this will be licensed in 2010 and the Defra funded Badger Vaccine Deployment Project will use this to develop practical know-how for vaccinating badgers and inform plans for future use of both injectable and oral badger TB vaccines. Development of cattle vaccines and oral badger vaccines continues. The earliest projected date for the use of a BCG cattle vaccine with a diagnostic test to Differentiate Infected from Vaccinated Animals (a so-called DIVA test) is mid to late 2015 with oral badger vaccines expected to be licensed around the same time. 2

3 Where to find information in this booklet Why a Badger Vaccine Deployment project? see page 5 The Catchment Areas see page 5 Targeting vaccination see page 7 How trapping and vaccination will be delivered see page 7 How long vaccination will be carried out for see page 9 Getting involved in the project see page 10 Outside the project deployment areas see page 11 Vaccinating badgers more harm than good? see page 11 Where to go for more information see page 13 3

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5 The Badger Vaccine Deployment Project Why a badger vaccine deployment project? Defra is funding a Badger Vaccine Deployment Project to assess the practicality of using the badger vaccine and to learn important lessons to support the long-term goal of a practical oral badger vaccine. By developing an understanding of how best to practically deploy vaccines, including how best to work with all stakeholders to deliver a vaccination programme and an understanding of training needs, we aim to build confidence in the principle and practicalities of vaccination. The project is not a scientific trial of how well the vaccine works in badgers, BCG has already been shown to have a protective effect which we anticipate will have a positive effect on the level of bovine TB in badgers. This will potentially reduce the risk of transmission from badgers to cattle and we will be examining cattle disease trends using routinely collected cattle TB data. However, no vaccine is 100% effective, so vaccination will need to be one of a range of tools to control TB in cattle. The Catchment Areas Six catchment areas of around 7 acres (300km 2 ) have been selected based on high historic TB incidence over the period 2003 to 2008, with a wide geographical spread of areas across the country. Within each area, badgers on up to 2 acres (100km 2 ) of cattle land will be vaccinated. The possible catchment areas were assessed by experts with field experience for practicality and suitability for trapping badgers. The areas were discussed with stakeholder groups and considered by the Bovine TB Eradication Group for England who made additional recommendations on suitability. The six catchment areas are: Staffordshire centred on Eccleshall, north west of Stafford Herefordshire/Worcestershire east of Tenbury Wells, north of Bromyard Gloucestershire Cotswold north east of Cheltenham, south west of Broadway 5

6 Gloucestershire north west of Stroud, south west of Gloucester, Lower Severn Valley Devon west of Tiverton Devon south east of Tiverton, northeast of Exeter The map below shows the location of the six catchment areas: 6

7 Targeting vaccination Defra and Fera (The Food and Environment Research Agency) will be inviting farmers in the six 7 acre (300km 2 ) catchment areas to participate. We aim to sign up participants on up to 2 acres (100km 2 ) of land on which to vaccinate badgers, in each of these areas. We want to target vaccination at badgers that might interact with cattle in order to maximise any potential benefits to participating farmers. Our approach is therefore not to blanket vaccinate the whole of the catchment areas but, instead, to target cattle farms and their immediate surrounds. This will lead to a more patchwork effect within the catchment area, as shown in the diagram below, and enable us to vaccinate on more farms overall. Participant Farms total area covered 2 acres 7 acres (300km 2 ) How trapping and vaccination will be delivered We aim to vaccinate as many badgers as possible that potentially access, or come into contact with badgers that access, participating farms. It is not necessary to trap and vaccinate every badger to provide protection. This is because it is difficult to maintain a chain of infection when large numbers of a population are immune. The stable social structure of badger groups, with limited mixing of individuals between groups, lends itself to the generation of this herd immunity through vaccination. An outline of the vaccination process is provided below: Participants will be signed up during autumn-winter 2009/10 and 2010/11 Participating cattle land and neighbouring land will be surveyed during winter Trapping and vaccination of badgers will take place during summer and autumn The traps will be placed at either the badger setts or on badger runs as close as possible to inaccessible setts 7

8 The traps will be baited, but not set, for up to ten nights, for the badgers to get used to going into them Trapping and vaccination will take place over about two nights for each sett this should be an adequate trapping time, as enough traps will be set to trap all the badgers from the sett; however, trapping could be carried out over more nights if necessary Vaccinated badgers will be temporarily marked using stock marker, and a marked badger retrapped in any given trapping session will be released without further vaccination to avoid wasting vaccine. There is no evidence that there would be a detrimental effect if a badger is injected again in subsequent years, or if infected badgers are vaccinated This trapping and vaccination process will be repeated annually, for five years, to enable newly born cubs to be vaccinated Trapping will be carried out during summer and autumn to make sure that cubs are vaccinated as soon as possible after birth, reducing the chance that they become infected before they are vaccinated. Later in the year, badgers are less likely to enter traps and so trapping is less effective. Sign-up and vaccination will be phased-in over two years. This means 2 acres (100%) of the Stroud area, 12,500 acres (50%) of a second area (Cheltenham) and acres (20%) of the other four areas will be vaccinated in the first year (2010), building up to 100% in all areas in year two (2011). This phasing-in process is shown in the diagram overleaf: 8

9 Area sign up and phasing Recruitment and sign up of landowners (approximate total area in acres) Survey land for badger setts (approximate total area in acres) Trap and vaccinate badgers (approximate total area in acres) Oct 2009 Jan 2010 May July Oct Nov May 2011 Nov 2011 Gloucestershire, Stroud area Gloucestershire, Cheltenham area Staffordshire area 12,500 12,500 12,500 12,500 12,500 20,000 20, Herefordshire / Worcestershire area Devon, W Tiverton area Devon, SE Tiverton area 20,000 20,000 20,000 20,000 20,000 20, Achieving 100% vaccination in all areas in 2011 will be dependent on getting the necessary level of contractors (please see overleaf for information on contractors) and participants signed up. If this isn t achieved within the second year, the phasing-in approach will continue into However, this will not shorten the length of time that vaccination takes place on a participating farm. How long vaccination will be carried out for Vaccination will be carried out for five years in each area. It will take a number of years for reduction in disease levels in badgers to translate into an impact on cattle disease. The vaccine does not cure already infected badgers these need to die off naturally for the infection risk to cattle from badgers to be reduced. Given that badgers commonly reach three to five years of age, it may take five years or more for a level of immunity to be reached in the badger population that will translate into a reduction in cattle herd breakdowns. 9

10 Getting involved in the project Contractors Fera will train contractors to carry out vaccination. The catchment area around Stroud and half the area around Cheltenham will be vaccinated as part of a training programme, giving contractors initial field experience under the guidance of Fera personnel. Fera has been trapping and injecting badgers for a number of years, so they have the expertise and skills required. Vaccination for the other areas will be carried out by contractors recruited through an EU tender process, run by Fera. By phasing in vaccination over two years, this will allow time to train contractors to carry out vaccination in the six areas. Anyone trapping and vaccinating badgers will need to be licensed under the Wildlife and Countryside Act 1981 and the Protection of Badgers Act Farmers Farmers are not being asked to vaccinate badgers themselves but are asked to grant access to their land. Taking part in the project is voluntary and the project is designed to be flexible and learn lessons each year rather than be a scientific experiment. Therefore, farmers will be able to review their involvement if any circumstances change. However, participants will be encouraged to take part for the full five years to maximise their chances of seeing benefits, as it will take time for badger vaccination to have a knock-on effect on the risk of disease to their cattle. The application and signing-up of participants in the catchment areas is being carried out by Fera, and the first stage of signing-up is during autumn-winter A further sign-up stage for remaining land in the areas will take place starting in autumn As badgers will be vaccinated on up to 2 acres (100km 2 ) of cattle and neighbouring land from within the larger catchment areas, not all farmers within the catchment areas will be able to participate in the project. 10 Farmers wishing to participate will need to meet the following criteria: Your land should fall primarily within one of the catchment areas You need to manage cattle or land adjacent to cattle land Your cattle herd must be on annual routine TB testing Your cattle herd must be up-to-date with TB testing when surveying of your land for badger setts is due to start

11 Farms do not necessarily have to be close to each other to get a benefit from vaccination but, for this project, contiguous land would be preferable as it is more practical and cost-effective for government to deploy a badger vaccine in this way. Therefore farms may be prioritised based on their location: Farms with all land parcels within a catchment area will be given priority over fragmented farms with land inside and outside of the catchment area Farms that are contiguous to each other, which creates a cluster of vaccinated farms, will also be given priority. To register an interest in participating, please contact Fera see contact details on page 13. Or, alternatively, please complete and send the tear off slip at the back of this booklet. Outside the deployment areas The injectable BCG vaccine for badgers is expected to be licensed in Once licensed, the vaccine will be available for purchase and use, by suitably trained and licensed personnel, outside the Defra-funded deployment areas. If landowners outside of the project catchment areas wish to use the vaccine, they will have to source and pay for licensed contractors to vaccinate badgers on their land. How this will work in practice is still being developed, but if you are outside the project areas and are interested in using the vaccine, you can register your interest by contacting Fera please see contact details on page 13. Vaccinating badgers more harm than good? How can the practical issues of trapping and vaccinating badgers be overcome? This is one of the questions the project aims to answer. It will develop practical know-how for vaccinating badgers and will provide an opportunity to learn how best to address any logistical issues. Fera has a vast amount of experience in trapping and vaccinating badgers, and they will be providing the training to contractors. 11

12 Is BCG safe for badgers? BCG is the most widely used human vaccine in the world, with an unparalleled safety record. Despite the very large number of animals, from a range of species, that have been vaccinated with BCG over many decades, there have been very few reports of adverse reactions. Will vaccinating badgers prevent bovine TB in cattle? Vaccination is a valuable tool when used as part of a range of control measures. Vaccinating badgers will be a risk reduction measure; it will reduce the risk of badgers catching TB and, therefore, will also potentially reduce the risk of transmission from badgers to cattle. However, it will take a number of years for a reduction in disease in badgers to be reflected in any reduction in disease incidence in cattle. Will trapping badgers make them more susceptible to infection or exacerbate disease in already infected badgers? Evidence from long term live-trapping studies where badgers are trapped, transported, anaesthetised, sampled and released suggests that any stress caused by the process does not exacerbate disease, or have measurable effects on their bovine TB susceptibility. Will vaccinated badgers excrete BCG, and potentially sensitise cattle to the skin test? Good Laboratory Practice safety studies have been carried out on the injectable badger vaccine, in which badgers were given at least ten times the dose that will be used in the deployment project. From these studies, there is no evidence that BCG is shed from vaccinated badgers and so it would, therefore, not be expected to compromise the use of the tuberculin skin test in cattle. Does cage trapping and vaccination cause perturbation? Trapping and vaccinating badgers is very unlikely to cause perturbation because badgers are not being removed from their social group. Removal of badgers, for example by culling, appears to lead to increased ranging by remaining badgers, and a breakdown of the normally stable pattern of badger social group territoriality. This in turn may have consequences for disease spread, through increased contact rates among badgers, and between badgers and cattle. Badgers have been trapped, anaesthetised, sampled and returned to their setts routinely as part of long-term research studies and perturbation of the badger population has not been observed. 12

13 Further Information For more information on the Badger Vaccine Deployment Project, including to register your interest in participating, please contact Fera. Online at By telephone By Or by post to Badger Vaccine Deployment Project Woodchester Park Research Station Tinkley Lane Nympsfield Gloucestershire GL10 3UJ Up-to-date information on the project, including maps of the catchment areas and a registration form to apply to participate in the project, is available on the Fera website: For more general information about bovine TB and TB control measures, please visit the Defra website: Or contact your local Animal Health Office 13

14 Please send me a sign-up form so I can register my interest in taking part in the Badger Vaccine Deployment Project. Name CPH Address Tel number Please indicate how you would prefer to be contacted Post

15 Badger Vaccine Deployment Project Woodchester Park Research Station Tinkley Lane Nympsfield Gloucestershire GL10 3UJ affix stamp here

16 Photograph: Badger photo supplied courtesy of Richard Yarnell. Map of catchments areas produced by the RADAR team, Defra. Further copies of this booklet are available free from Defra publications phone or quoting the PB number below. Published October 2009 PB13306 Nobel House 17 Smith Square London SW1P 3JR