Funding for this research was provided by:
Medical Research Council (MR/T027150/1)
Received: 8 February 2022
Accepted: 11 April 2022
First Online: 25 April 2022
: The University of Bristol’s Faculty of Health Sciences, the London School of Hygiene and Tropical Medicine’s Research Ethics Committees and the National Health Service Health Research Authority provided approvals for the study (references 99102, 21887 & 279670 respectively). For participants aged 16 years and over, informed written or verbal consent was obtained prior to participating in a research activity. Where participants were aged below 16 years, parental consent in addition to adolescent assent was obtained, either written or verbally.
: Not applicable.
: The authors declare there are no competing interests.