1. Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom;
2. Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom;
3. Liverpool University Hospitals National Health Service Foundation Trust, Liverpool, United Kingdom;
4. UCL Respiratory, Division of Medicine, University College London, London, United Kingdom;
5. Division of Infection and Immunity, University College London, London, United Kingdom;
6. Antigen Discovery Inc, Irvine, California; and
7. Malawi Liverpool Wellcome-Trust Programme, Blantyre, Malawi