title: Oral Vaccination of Free-Living Badgers (Meles meles) with Bacille Calmette Guérin (BCG) Vaccine Confers Protection against Tuberculosis.
abstract: A field trial was conducted to investigate the impact of oral vaccination of free-living badgers against natural-transmitted Mycobacterium bovis infection. For a period of three years badgers were captured over seven sweeps in three zones and assigned for oral vaccination with a lipid-encapsulated BCG vaccine (Liporale-BCG) or with placebo. Badgers enrolled in Zone A were administered placebo while all badgers enrolled in Zone C were vaccinated with BCG. Badgers enrolled in the middle area, Zone B, were randomly assigned 50:50 for treatment with vaccine or placebo. Treatment in each zone remained blinded until the end of the study period. The outcome of interest was incident cases of tuberculosis measured as time to seroconversion events using the BrockTB Stat-Pak lateral flow serology test, supplemented with post-mortem examination. Among the vaccinated badgers that seroconverted, the median time to seroconversion (413 days) was significantly longer (p = 0.04) when compared with non-vaccinated animals (230 days). Survival analysis (modelling time to seroconversion) revealed that there was a significant difference in the rate of seroconversion between vaccinated and non-vaccinated badgers in Zones A and C throughout the trial period (p = 0.015). For badgers enrolled during sweeps 1-2 the Vaccine Efficacy (VE) determined from hazard rate ratios was 36% (95% CI: -62%- 75%). For badgers enrolled in these zones during sweeps 3-6, the VE was 84% (95% CI: 29%- 97%). This indicated that VE increased with the level of vaccine coverage. Post-mortem examination of badgers at the end of the trial also revealed a significant difference in the proportion of animals presenting with M. bovis culture confirmed lesions in vaccinated Zone C (9%) compared with non-vaccinated Zone A (26%). These results demonstrate that oral BCG vaccination confers protection to badgers and could be used to reduce incident rates in tuberculosis-infected populations of badgers.
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Eamonn
authors.initials: E
authors.lastname: Gormley
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Ní Bhuachalla
authors.affiliation: Dept of Agriculture, Food and the Marine, Head of Wildlife Unit, Agriculture House, Dublin, Ireland.
authors.forename: James
authors.initials: J
authors.lastname: O'Keeffe
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Denise
authors.initials: D
authors.lastname: Murphy
authors.affiliation: Immune Solutions Ltd, Centre for Innovation, University of Otago, Dunedin, New Zealand.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Aldwell
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Tara
authors.initials: T
authors.lastname: Fitzsimons
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Stanley
authors.affiliation: UCD Centre for Veterinary Epidemiology and Risk Analysis (CVERA), School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Tratalos
authors.affiliation: UCD Centre for Veterinary Epidemiology and Risk Analysis (CVERA), School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Guy
authors.initials: G
authors.lastname: McGrath
authors.affiliation: Central Veterinary Research Laboratory, Backweston, Co. Kildare, Ireland.
authors.forename: Naomi
authors.initials: N
authors.lastname: Fogarty
authors.affiliation: Central Veterinary Research Laboratory, Backweston, Co. Kildare, Ireland.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kenny
authors.affiliation: UCD Centre for Veterinary Epidemiology and Risk Analysis (CVERA), School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: More
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Locksley L McV
authors.initials: LL
authors.lastname: Messam
authors.affiliation: School of Veterinary Medicine, University College Dublin (UCD), Dublin, Ireland.
authors.forename: Leigh A L
authors.initials: LA
authors.lastname: Corner
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000835:Animals, Wild; D001500:BCG Vaccine; D045969:Mustelidae; D009163:Mycobacterium bovis; D014376:Tuberculosis / Q000517:prevention & control / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary*
chemical_list: D001500:BCG Vaccine