Trajectories of PrEP Adherence Among Young Women Aged 16 to 25 in Cape Town, South Africa.

Despite demonstrated efficacy for HIV prevention, substantial challenges remain for the successful rollout of oral pre-exposure prophylaxis (PrEP), especially among adolescent girls and young women (AGYW). We characterized trajectories of PrEP adherence among 200 AGYW in South Africa and analyzed data from 22 qualitative interviews and 3 focus group discussions for explanatory purposes. Two adherence trajectory groups were identified: 52% with high early adherence that declined after month three and 48% with low adherence throughout. Adherence in the "consistently low" group was related to social support and logistical concerns, while the decrease in the "high declining" group corresponded to a change in the frequency of study visits from monthly to quarterly. PrEP support should be differentiated for those who need more frequent visits and adherence support initially versus later in PrEP use. Visits every month, when needed, should be considered for AGYW who need sustained support later into use.