Received: 23 September 2020
Accepted: 20 December 2020
First Online: 13 January 2021
Ethics approval and consent to participate
: The study was ethically approved by the Institutional Review Board of the Nigerian Institute of Medical Research, Lagos and the Senegalese National Ethics committee. Written informed consent and/or assent was obtained from the parents and guardian of children prior to recruitment.
: Not applicable.
: The authors declare that they have no competing interests.