Funding for this research was provided by:
Foundation for the National Institutes of Health (1U01AI110466-01A1)
Bill and Melinda Gates Foundation (OPP1017579, OPP1017641)
Received: 28 November 2019
Accepted: 20 April 2020
First Online: 12 May 2020
Ethics approval and consent to participate
: Both this study (585/2015) and parent study, DCHS (401/2009), received ethical approval from the Faculty of Health Sciences, Human Research Ethics Committee (HREC) of the University of Cape Town, South Africa. The relevant guidelines and regulations were followed during the performance of all experiments. Mothers participating in the DCHS provided informed, written consent for enrolment of their infants at the time of delivery and annually.
: Not applicable.
: The authors declare that they have no competing interests related to the content of this paper. All the authors reviewed and agreed with the content of the final version of the manuscript prior its submission for publication.