1 NDM Research Building, Nuffield Department of Medicine, University of Oxford, Old Road Campus, Oxford, OX3 7FZ, UK; King's College Hospital, Denmark Hill, London, SE5 9RS, UK. Electronic address: angela.mcbride@ndm.ox.ac.uk.
2 Hospital for Tropical Diseases, University College London Hospitals, London, UK; London School of Hygiene and Tropical Medicine, London, UK.
3 Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, UK.
4 Hospital for Tropical Diseases, University College London Hospitals, London, UK; Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, UK.
5 Department of Virology, University College London Hospitals, London, UK; Rare and Imported Pathogens Laboratory, UK Health Security Agency, Porton Down, UK.