Prevalence and factors associated with uptake of pre-exposure prophylaxis amongst women vulnerable to HIV who received HIV antibodies in Antibody Mediated Prevention HVTN703/HPTN081 trial in Harare, Zimbabwe: a cross-sectional study.

Introduction: There is limited evidence on pre-exposure prophylaxis (PrEP) uptake post-trial participation for women vulnerable to HIV. This study investigates the prevalence and factors associated with PrEP uptake post-participation in an HIV prevention trial. Methods: Former Antibody Mediated Prevention (AMP) study participants were invited to the three AMP clinical research sites in Zimbabwe after at least a year of exiting the study. The AMP study evaluated the safety and efficacy of Vaccine Research Center 01 broadly neutralising monoclonal antibody in reducing acquisition of HIV-1 infection in women in sub-Saharan Africa. Participants vulnerable to HIV were enrolled and risk reduction counselling was done throughout study participation. In a cross-sectional study, semi-structured interview administered questionnaires were completed. The primary outcome was uptake of PrEP after the study exit. Results: From February 2022 to August 2022, out of 434 participants enrolled in the AMP study, a total of 298 were invited and 225 participated in the study; 28% made an attempt to access PrEP after study participation, 20% used PrEP at some point after study participation and 15% were on PrEP at the time of questionnaire administration. PrEP uptake was associated with new sexual partners after study participation and higher average number of sexual encounters in the previous month. Challenges faced in accessing PrEP included those related to the health facility, transport problems and stigma. Conclusion: The majority (85%) of former AMP participants were not on PrEP at the time of questionnaire administration. We observed poor uptake of PrEP post-study exit among participants who had received risk reduction counselling through study duration. Measures to improve PrEP uptake should be considered on participants vulnerable to HIV when exiting HIV prevention trials.

Pharmacokinetic-pharmacodynamic modelling of atazanavir in hair among adolescents on antiretroviral treatment in Zimbabwe.

BACKGROUND: Drug potency is a pharmacological parameter defining dose or concentration of drug required to obtain 50% of the drug's maximal effect. Pharmacokinetic-pharmacodynamic modelling and simulation allows estimation of potency and evaluate strategies improving treatment outcome. The objective of our study is to determine potency of atazanavir in hair, defined as atazanavir level in hair associated with 50% probability of failing to achieve viral load below 1000 copies/ml among adolescents, and explore the effect of participant specific variables on potency. METHODS: A secondary analysis was performed on data from a previous study conducted in HIV-infected adolescents failing 2nd line ART from Harare central hospital, Zimbabwe, between 2015 and 2016. We simulated atazanavir concentrations in hair using NONMEM (version 7.3) ADVAN 13, based on a previously established pharmacokinetic model. Logistic regression methods were used for PKPD analysis. Simulations utilising PKPD model focused on estimation of potency and exploring the effect of covariates. RESULTS: The potency of atazanavir in hair was found to be 4.5 ng/mg hair before adjusting for covariate effects. Participants at three months follow-up, reporting adequate adherence, having normal BMI-for-age, and cared for by mature guardians had increased potency of atazanavir in hair of 2.6 ng/mg, however the follow-up event was the only statistically significant factor at 5% level. CONCLUSION: Atazanavir in hair in the range 2.6 to 4.5 ng/mg is associated with above 50% probability of early viral load suppression. Adherence monitoring to adolescents with lower potency of atazanavir is recommended. The effect self-reported adherence level, BMI-for-age, and caregiver status require further evaluation.

IMPAACT 2016: Operationalizing HIV Intervention Adaptations to Inform the Science and Outcomes of Implementation.

Introduction: Uptake of evidence-based interventions for adolescents and young adults living with HIV (AYA-LWH) in sub-Saharan Africa (SSA) is complex, and cultural differences necessitate local adaptations to enhance effective implementation. Few models exist to guide intervention tailoring, yet operationalizing strategies is critical to inform science and implementation outcomes, namely acceptability, appropriateness, feasibility, fidelity, and sustainability. This paper describes operationalizing the ADAPT-ITT framework applied to a manualized trauma-informed cognitive behavioral therapy (TI-CBT) intervention addressing mental and sexual health for AYA-LWH in SSA in preparation for a randomized controlled trial (RCT). Methods: Phase 1 of the RCT focused on operationalizing ADAPT-ITT steps 3-7 to tailor the intervention for use in eight sites across Botswana, Malawi, South Africa, and Zimbabwe. Well-defined processes were developed to supplement the general guidelines for each step to provide clear, consistent direction on how to prepare and conduct each step, including documenting, assessing, and determining adaptations, while maintaining intervention fidelity. The processes provided efficient standardized step-by-step progression designed for future replication. All sites participated in Phase 1 using the created tools and strategies to translate and present the TI-CBT to community stakeholders for feedback informing local adaptations. Results: The research team developed and operationalized materials guiding adaptation. A translation review process verified local adaptability, maintained core concepts, and revealed differing interpretations of words, idioms, and culturally acceptable activities. Strategically designed tools comprised of feedback and translation verification forms resulted in meticulous management of adaptations. Robust collaborations between investigators, research managers, site personnel, and topical experts maximized multidisciplinary expertise, resulting in ~10-15 personnel per site facilitating, collecting, assessing, and integrating local feedback. Processes and tools operationalized in steps 3-7 effectively addressed implementation outcomes during community engagements (n = 108), focus groups (n = 5-8 AYA-LWH and caregivers per group), and strategic training of youth leaders. Discussion: This paper offers a novel generalizable approach using well-defined processes to guide intervention adaptation building on the ADAPT-ITT framework. The processes strengthen the science of implementation and provide much-needed specificity in adaptation steps to optimize and sustain real-world impact and help researchers and community stakeholders maximize existing infrastructure, culture, and resources to inform implementation strategies.

A population pharmacokinetic model is beneficial in quantifying hair concentrations of ritonavir-boosted atazanavir: a study of HIV-infected Zimbabwean adolescents.

BACKGROUND: Adolescents experience higher levels of non-adherence to HIV treatment. Drug concentration in hair promises to be reliable for assessing exposure to antiretroviral (ARV) drugs. Pharmacokinetic modelling can explore utility of drug in hair. We aimed at developing and validating a pharmacokinetic model based on atazanavir/ritonavir (ATV/r) in hair and identify factors associated with variabilities in hair accumulation. METHODS: We based the study on secondary data analysis whereby data from a previous study on Zimbabwean adolescents which collected hair samples at enrolment and 3 months follow-up was used in model development. We performed model development in NONMEM (version 7.3) ADVAN 13. RESULTS: There is 16% / 18% of the respective ATV/r in hair as a ratio of steady-state trough plasma concentrations. At follow-up, we estimated an increase of 30% /42% of respective ATV/r in hair. We associated a unit increase in adherence score with 2% increase in hair concentration both ATV/r. Thinner participants had 54% higher while overweight had 21% lower atazanavir in hair compared to normal weight participants. Adolescents receiving care from fellow siblings had atazanavir in hair at least 54% less compared to other forms of care. CONCLUSION: The determinants of increased ATV/r concentrations in hair found in our analysis are monitoring at follow up event, body mass index, and caregiver status. Measuring drug concentration in hair is feasibly accomplished and could be more accurate for monitoring ARV drugs exposure.

Evaluating an enhanced adherence intervention among HIV positive adolescents failing atazanavir/ritonavir-based second line antiretroviral treatment at a public health clinic.

Sustaining virological suppression among HIV-infected adolescents is challenging. We evaluated a home-based adherence intervention and characterized self-reported adherence, virological response and drug resistance among adolescents failing atazanavir/ritonavir (ATV/r)-based 2nd line treatment. METHODS: HIV-positive adolescents (10-18 years) on ATV/r-based 2nd line treatment with virological failure (viral load (VL) ≥1 000 copies/ml) were randomized to either standard care (SC) or SC with addition of modified directly administered antiretroviral therapy (mDAART) for 90 days. VL was measured and questionnaires were administered at study entry and at 3 months. Genotyping was done for participants with continued failure. Primary outcome was suppression to VL < 1 000 copies/ml. RESULTS: Fifty adolescents aged 10-18 years on 2nd line treatment for >180 days were enrolled, 23(46%) were randomized to mDAART and 27(54%) to SC. Fifty-four percent were female; mean age was 15.8 years; mean baseline VL was 4.8(log10) copies/ml; 40% reported adherence <80% in previous 1 month at baseline; 40% suppressed (VL <1 000 copies/ml) after follow-up. mDAART resulted in significantly increased self-reported adherence (RR= 0.1; 95% CI=0.02-0.8, p=0.023); closely following dosing schedule (RR= 4.8; 95% CI=1.6-13.8, p=0.004); VL decrease (p=0.031) and modest increase in virological suppression to <1 000 copies/ml (p=0.105). Genotyping in 28/30 participants with continued virological failure demonstrated high level atazanavir resistance (I50L, N88S and I84V) in 6(21%); 3(11%) of whom also had high level resistance to lopinavir and darunavir (V32I, I50L, I54V, 147V and V82A). DISCUSSION: The mDAART intervention modestly improved virological suppression among adolescents with ATV/r-based 2nd line treatment failure, significantly increased self-reported adherence and decreased viral load. High level ATV/r resistance was demonstrated. CONCLUSION: Targeting mDAART to adolescents who are virologically failing PI-based 2nd line treatment decreases viral load and increases self-reported adherence. Early drug-resistance testing could reduce morbidity and mortality.