University of Southampton, Newcastle University, University of Liverpool - Institute of Infection and Global Health, Government of the United Kingdom - Chelsea and Westminster Hospital NHS Foundation Trust, King’s College London - Institute of Psychiatry, Psychology and Neuroscience, University of Utah - Department of Medicinal Chemistry, Newcastle University, Encephalitis International, King’s College London - Institute of Psychiatry, Psychology & Neuroscience (IoPPN), University College London, University of Cambridge, University College London, University of Edinburgh, University of Cambridge - Division of Anaesthesiology, King’s College London, University College London, University of Edinburgh, The University of Manchester, University of Oxford, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, Alder Hey Children's NHS Foundation Trust - Department of Neurology, University College London - MRC Clinical Trials Unit, Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK, Newcastle University and University of Liverpool - Institute of Infection and Global Health

University of Liverpool - Institute of Infection and Global Health, University College London - UCL Queen Square Institute of Neurology, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, Encephalitis International, Alder Hey Children's NHS Foundation Trust, Tropical and Infectious Diseases Unit, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool, UK, Government of the United States of America - Division of High Consequence Pathogens and Pathology and University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences

King’s College London - Institute of Psychiatry, Psychology and Neuroscience, University of Liverpool - Institute of Infection and Global Health, University of Liverpool - Institute of Infection and Global Health, University of Liverpool - Institute of Infection and Global Health, Newcastle University, Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK, University College London - MRC Clinical Trials Unit, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, King’s College London - Institute of Psychiatry, Psychology and Neuroscience, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences and King’s College London

University of Southampton, University of Southampton, University of Southampton, NHS Foundation Trust - Aintree University Hospital, University of Liverpool, University of Liverpool - Liverpool Clinical Trials Centre, University of Southampton - University Hospital Southampton NHS Foundation Trust, The University of Manchester, King’s College London - Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Government of the United Kingdom - Chelsea and Westminster Hospital NHS Foundation Trust, University College London, Encephalitis International, University of Liverpool, University College London, University of Cambridge, University of Cambridge - Division of Anaesthesiology, University of Southampton, University of Southampton, University of Liverpool - Institute of Infection and Global Health, Newcastle University, King’s College London - Institute of Psychiatry, Psychology & Neuroscience (IoPPN), UCL Institute of Neurology - Centre for Neuromuscular Disease, University College London - MRC Center for Neuromuscular Diseases, NHS Foundation Trust - Poole, North Middlesex University Hospital, Imperial College Healthcare NHS Trust - Department of Neuroradiology, Southmead Hospital - Department of Neurology, University Hospital Southampton NHS Foundation Trust - Wessex Neurological Centre - Department of Neurology, University of Edinburgh, University of Edinburgh, University College London, University of Oxford, University College London, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, Alder Hey Children's NHS Foundation Trust - Department of Neurology, University College London - MRC Clinical Trials Unit, Newcastle University, University of Liverpool - Institute of Infection and Global Health and Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK

University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool - Department of Health Data Scienc, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool - Institute of Infection and Global Health, Chelsea and Westminster Hospital - Department of Neurology, Encephalitis International, University of London - Institute of Infection and Immunity, The Walton Centre NHS Foundation Trust, The Walton Centre NHS Foundation Trust - Department of Neurology, University of Liverpool, University of Liverpool - Department of Health Data Science, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Exeter - Health Economics Group, Encephalitis International, Liverpool University Hospitals NHS Foundation Trust (LUH) - Tropical and Infectious Disease Unit, University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences, University of Oxford, Independent, University of Liverpool - Department of Health Data Science and University of Liverpool - Institute of Infection, Veterinary and Ecological Sciences