1. Nuffield Department of Medicine, The Jenner Institute; University of Oxford, Old Road Campus Research Building, Roosevelt Drive; Oxford OX3 7DQ UK
2. Nuffield Department of Medicine, MRC Human Immunology Unit; Weatherall Institute of Molecular Medicine, University of Oxford, The John Radcliffe; Oxford OX3 9DS UK
3. Nuffield Department of Medicine, The Sir William Dunn School of Pathology; University of Oxford, South Parks Road; Oxford OX1 3RE UK
4. Department of Microbiology; Tumor and Cell Biology, Karolinska Institutet; Stockholm Sweden
5. Departement of Immunohematology and Blood Transfusion; Leiden University Medical Centre; Leiden the Netherlands