Competing interests: The BMJ has judged that there are no disqualifying financial ties to commercial companies. The authors declare the following other interests: AN receives research funding from UKRI, Wellcome, EC, EDCTP, UK DHSC, WHO, IDRC, and ANRS. SV has funding from UKRI, IOI, and PSI. PH has finding from Bill & Melinda Gates Foundation, EDCTP, European Commission, FCDO, National Philanthropic Trust, Mastercard Foundation, Moh Family Foundation, Wellcome Trust, UKRI, and National Institute for Health Research. He participates in an expert panel for Vir Biotechnology for therapeutic antibody development for infectious diseases, and has provided expert advice to Clyde and Co on interpretation of terminology related to new and emerging respiratory diseases. Further details of The BMJ policy on financial interests are here: https://www.bmj.com/sites/default/files/attachments/resources/2016/03/16-current-bmj-education-coi-form.pdf