Funding for this research was provided by:
Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD103466.)
Received: 5 October 2020
Accepted: 12 October 2020
First Online: 5 November 2020
Ethics approval and consent to participate
: This study was approved by the Human Research Ethics Committee of the University of the Witwatersrand, and the institutional review boards of Vanderbilt University and Boston University. As the study will utilize only routinely-collected laboratory data that are accessible for surveillance purposes, no individual patient consent will be sought.
: Not applicable.
: The authors declare that they have no competing interests.