Funding for this research was provided by:
Bill and Melinda Gates Foundation (OPP1149259)
Text and Data Mining valid from 2019-12-01
Received: 22 January 2019
Accepted: 15 November 2019
First Online: 2 December 2019
Ethics approval and consent to participate
: This research was conducted with approval from the Federal Ministry of Health Abuja, Nigeria, the State Ministry of Health Gombe State, Nigeria and the London School of Hygiene & Tropical Medicine (reference 12181). The free and signed informed consent of all interviewees was obtained.
: Not applicable.
: The authors declare that they have no competing interests.