Catalysing Access to New HIV Prevention Products to Stop HIV (CATALYST)


The CATALYST implementation science study, part of the MOSAIC Project, spans several sub-Saharan African countries (South Africa, Lesotho, Kenya, Zimbabwe, and Uganda). It aims to empower women in these regions to prevent HIV by accelerating the adoption and expansion of new biomedical prevention tools, such as pre-exposure prophylaxis (PrEP). The study’s goal is to furnish decision-makers with evidence that facilitates the delivery of PrEP choices and illuminates how clients utilize PrEP when presented with options among different products.

The CATALYST study seeks to characterize and evaluate the implementation of an enhanced service delivery package that offers informed choices among three PrEP products: oral PrEP, PrEP ring, and CAB PrEP (injectable PrEP). This effort spans five African nations and consists of two primary components: a prospective cohort of PrEP users and a mixed-methods process evaluation.

The CATALYST initiative includes four nested studies:

  1. Preventive Effective Use (PEU): Evaluating the feasibility and accuracy of a PEU measure to gauge participants’ PrEP utilization.
  2. HIV Testing Algorithms for CAB PrEP: Investigating alternative HIV testing strategies for CAB PrEP initiators.
  3. Community Acceptability: Examining the influence of PrEP influencers (parents, partners, caregivers) on PrEP uptake.
  4. Costing Study (except in South Africa): Determining the costs associated with providing PrEP choice, both average and incremental.

Overall, the study aims to deliver PrEP choice across multiple products to women, building upon existing PrEP service models and aligning with national guidelines. It implements an enhanced service delivery package supporting PrEP choice at various levels—individual, provider, facility, and community. Through quality improvement mechanisms and capacity building, the study refines its service delivery package over time.



  • Kristine Torjesen, Project Director and Principal Investigator
  • Elizabeth Irungu – CATALYST Co-Investigator

South Africa:

  • Nicolette Naidoo, Country Lead and Principal Investigator
  • Saiqa Mullick, Country Director and Co-Investigator
  • Roisin Drysdale, National Study Lead Coordinator

Latest Update

March 2024

Click here for further details regarding the CATALYST Study.

For more details about CATALYST Study please email

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