1. Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
2. Norwegian Institute of Public Health, Oslo, Norway
3. School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
4. National Institute for Biological Standards and Control, Hertfordshire, United Kingdom
5. Department of Zoology, University of Oxford, Oxford, United Kingdom