Study design and participants
REACH was a phase 2a, randomized, open‐label, crossover study conducted at four research sites in Cape Town and Johannesburg, South Africa; Kampala, Uganda; and Harare, Zimbabwe from January 2019 to September 2021. The primary objectives were to collect safety and adherence data for the ring and oral PrEP among AGYW and to understand a preference for the two products. The trial enrolled 247 HIV‐negative participants ages 16–21 years assigned female at birth. Participants were randomized 1:1 to use the ring or oral PrEP for one 6‐month period, then switched to the other product for a second 6‐month period.  In the third and final 6‐month period, participants could choose to use the ring, oral PrEP or neither product, and could switch products at any time. Detailed methods, participant characteristics and primary findings have been previously reported [