INTRODUCTION:
Preventing HIV acquisition during pregnancy and breastfeeding remains a major health systems priority in sub-Saharan Africa1. Integrating pre-exposure prophylaxis (PrEP) into primary health care (PHC) services offers an opportunity to strengthen person-centred HIV prevention2. Prior research has demonstrated feasability3, but little is known about how integration processes and frontline health care workers’ (HCWs) perceptions and experiences shape implementation.

METHODS:
This qualitative sub-study, nested within a PrEP implementation project in Cape Town, South Africa, explored how PrEP integration unfolded within selected antenatal and postnatal clinics. In part 1, a document analysis of policy and training materials was conducted using Valentijn’s Rainbow Model of Integrated Care4 to examine intended integration across clinical, professional, organisational and system levels. In part 2, a secondary analysis was conducted on data from interview and focus-group discussions conducted with participating HCWs. A deductive-inductive analytic approach captured emergent themes, and Sekhon’s Theoretical Framework of Acceptability (TFA)5 allowed the interpretation of these insights in a real-world context.

RESULTS:
Gaps emerged between intended design and delivery of integrated services. HCWs viewed PrEP delivery as aligned with PHC goals but reported substantial burdens and opportunity costs that compromised acceptability. Mentorship strengthened capacity but was at times experienced as supervisory, limiting professional autonomy. Systemic constraints – limited human resources, competing programme demands and inconsistent organisational support – were key determinants of whether PrEP could be delivered as an integrated, sustainable component of maternity care.

CONCLUSIONS:
The integration intervention was broadly viewed as acceptable by HCWs, but this acceptability was shaped unevenly across the TFA constructs. HCWs understood PrEP and its purpose (intervention coherence), affective attitudes were positive and they generally believed PrEP to be effective (perceived effectiveness). However, high perceived burden and substantial opportunity costs undermined initial positive attitudes and self-efficacy altered as implementation progressed.