1. Immunize.org (formerly Immunization Action Coalition), Saint Paul, MI, USA
2. Public Health and Immunisation, Glasgow, UK
3. Three-C Consulting Group, Harleysville, PA, USA
4. Royal College of General Practitioners and British Global & Travel Health Association, Wokingham, UK
5. Lifespan and Population Health Unit, School of Medicine, University of Nottingham, Nottingham, UK