Funding for this research was provided by:
National Institutes of Health (T32CA09168)
Bill and Melinda Gates Foundation (OPP1157270)
National Institute for Health Research Health Protection Research Unit in Immunisation (HPRU-2012-10096)
Article History
Received: 13 July 2019
Accepted: 12 November 2019
First Online: 14 January 2020
Ethics approval and consent to participate
: Not applicable.
: Not applicable.
: The authors declare that they have no competing interests.