1. The Jenner Institute, University of Oxford, Oxford OX1 2JD, UK
2. KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
3. Wageningen Bioveterinary Research, Lelystad, The Netherlands
4. Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
5. Wellcome Centre for Human Genetics, Division of Structural Biology, University of Oxford, Oxford OX1 2JD, UK
6. Centre for Tropical Medicine and Global Health, University of Oxford, Oxford OX1 2JD, UK