Received: 22 November 2019
Accepted: 27 July 2020
First Online: 5 August 2020
Ethics approval and consent to participate
: We sought ethical clearance to use archived participants’ data and serum from the Muhimbili University of Health and Allied Sciences and Mbeya Medical Research and Ethics Committees (MMReC). We observed confidentiality, and no unauthorized persons had access to the collected data. Each subject was assigned a study identification number that was not linked to individual names.
: Not applicable.
: The authors declare that they have no competing interests.