Field evaluation of candidate baits for oral delivery of BCG vaccine to European badgers, Meles meles.

Author's accepted versionFinal version available from Elsevier via the DOI in this recordThe control of tuberculosis (TB) in cattle in the UK and Ireland is compromised by transmission of Mycobacterium bovis to cattle from the European badger (Meles meles), which acts as a wildlife reservoir. Vaccination of badgers could potentially contribute to TB control but the only licensed vaccine is injectable BadgerBCG which requires the live-capture of badgers. Current research is aimed at developing an oral TB vaccine (where vaccine is contained within bait) that is intended to be more cost-effective to deploy over large areas. In order to identify a lead product, candidate baits identified from captive badger studies were evaluated in three successive bait screening studies with wild badgers. A fourth field study, using the lead candidate bait and biomarkers, investigated the effectiveness of different carriers for their potential to deliver liquid payloads (vaccine surrogate). In each field study, bait disappearance was monitored daily for ten days and remote video surveillance was used to determine preference (i.e. the order in which baits were taken). In the carrier study, biomarkers were used to determine what proportion of subsequently trapped badgers had ingested the bait and the vaccine-carrier biomarker payload. Across all four studies, 79% (3397/4330) of baits were taken by badgers although the number varied significantly by badger social group and bait type. In all studies, bait disappearance increased over time, with 75-100% of baits being taken by day ten. In the carrier study, 75% (9/12) of trapped badgers tested positive for at least one of the biomarkers and the type of carrier did not influence bait attractiveness. Together with data from complementary laboratory and captive animal studies, this study identified a highly attractive and palatable bait (peanut-based paste bait; PT) and vaccine-carrier (hydrogenated peanut oil; HPO) combination with the potential to deliver a liquid vaccine to wild badgers.The authors would like to thank Pest Tech Ltd. (New Zealand), Connovation Ltd. (NZ), Immune Solutions Ltd. (NZ), Icthus Industries (USA), Zapi Industrie (Italy) and IDT Biologika (Germany) for supplying bait and carrier materials for these studies, and the field team at Woodchester Park. All work involving live badgers was carried out under a UK Home Office licence, in accordance with the Animals (Scientific Procedures) Act 1986 and was subject to an internal ethical review process. This study was funded by Defra

The ecology of the European badger (Meles meles) in Ireland: a review

peer-reviewedThe badger is an ecologically and economically important species. Detailed knowledge of aspects of the ecology of this animal in Ireland has only emerged through research over recent decades. Here, we review what is known about the species' Irish populations and compare these findings with populations in Britain and Europe. Like populations elsewhere, setts are preferentially constructed on south or southeast facing sloping ground in well-drained soil types. Unlike in Britain, Irish badger main setts are less complex and most commonly found in hedgerows. Badgers utilise many habitat types, but greater badger densities have been associated with landscapes with high proportions of pasture and broadleaf woodlands. Badgers in Ireland tend to have seasonally varied diets, with less dependence on earthworms than some other populations in northwest Europe. Recent research suggests that females exhibit later onset and timing of reproductive events, smaller litter sizes and lower loss of blastocysts than populations studied in Britain. Adult social groups in Ireland tend to be smaller than in Britain, though significantly larger than social groups from continental Europe. Although progress has been made in estimating the distribution and density of badger populations, national population estimates have varied widely in the Republic of Ireland. Future research should concentrate on filling gaps in our knowledge, including population models and predictive spatial modelling that will contribute to vaccine delivery, management and conservation strategies.Department of Agriculture, Fisheries and FoodTeagasc Walsh Fellowship Programm