Ethical consideration
The University of KwaZulu-Natal Biomedical Research Ethics Committee (BFC043/15) and the South African Medical Research Council Ethics Review Committee (EC006-2/2015) provided ethics approval to conduct the main trial. All participants provided written informed consent. The use of data for the present study was approved by the Biomedical Research Ethics Committee at the University of KwaZulu-Natal (00002795/2021). The trial was registered with ClinicalTrials.gov (NCT03022370).