affiliation not provided to SSRN, Enhancing Care Foundation, University College London - MRC Clinical Trials Unit, affiliation not provided to SSRN, affiliation not provided to SSRN, Moi University, University College London - MRC Clinical Trials Unit, affiliation not provided to SSRN, Joint Clinical Research Centre, Moi University, University of KwaZulu-Natal, Fondazione Penta ETS, affiliation not provided to SSRN, London School of Hygiene & Tropical Medicine - Department of Global Health and Development, Joint Clinical Research Centre, University of York, Baylor University - Children's Foundation Uganda, University College London - MRC Clinical Trials Unit, University College London - MRC Clinical Trials Unit, University College London - MRC Clinical Trials Unit and Baylor University - Children's Foundation Uganda