1. Bristol Veterinary School, University of Bristol, Bristol BS40 5DU, UK
2. NIHR Health Protection Research Unit (HPRU) in Behavioural Science and Evaluation, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 2BN, UK
3. Department of Engineering Mathematics, University of Bristol, Bristol BS8 1TW, UK
4. Centre for Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
5. MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, UK
6. Department of Mathematics, University of Manchester, Manchester M13 9PL, UK
7. The Alan Turing Institute, London, UK