University College London - Institute for Global Health, University of Ibadan - Department of Paediatrics, University of Melbourne - Department of General Medicine, University of Ibadan, University College Hospital Ibadan, Independent, University of Pittsburgh, University College London, Save the Children International, Nigeria, Save the Children International, Nigeria, Save the Children International, Nigeria, Save the Children International, Nigeria, Save the Children, UK, Save the Children, UK, Save the Children, UK, GlaxoSmithKline, University of Ibadan, University College London, Karolinska Institutet - Department of Global Public Health and Independent