1. Southmead Hospital; North Bristol NHS Trust; Department of Immunology; Bristol UK
2. School of Mathematics; University of Bristol; Bristol UK
3. Research Department of Infection and Population Health; Institute for Global Health; University College London; London UK
4. National Institute for Health Research (NIHR) Health Protection Research Unit (HPRU) in Blood Borne and Sexually Transmitted Infections at University College London; London UK
5. HIV i-Base; London UK
6. Department of Population Health Sciences; Bristol Medical School; University of Bristol; Bristol UK
7. National Institute of Health Research (NIHR) Health Protection Research Unit (HPRU) in Evaluation of Interventions at University of Bristol; Bristol UK