Potential impact of catch-up HPV vaccination on HPV prevalence and cervical cancer incidence among women living with HIV in South Africa: results from two mathematical models

Abstract Introduction Women living with HIV (WLHIV) face an increased risk of cervical cancer (CC). With inequitable HPV vaccine access and a programmatic focus on girls-only school-based delivery, many WLHIV in high HIV prevalence countries remain vulnerable to HPV infection and CC. We assessed the incremental impact of adding catch-up vaccination for WLHIV in South Africa. Methods We used two independently developed HPV/CC and HIV transmission models to predict the incremental impact of catch-up HPV vaccination for WLHIV compared to routine-only vaccination of girls aged 9-14 (90% cohort coverage) from 2020 onward using a nonavalent vaccine (lifelong 100% protection). We assessed two catch-up scenarios vaccinating WLHIV aged 15-24 or 15+ (attaining 90% cohort coverage for at least three years), maintaining baseline CC screening. We report the predicted median annual prevalence of vaccine-type high-risk HPV (VT HR-HPV), CC incidence, and cumulative fraction of CC averted compared to routine-only vaccination among WLHIV overall (age-standardized) and by age. Results With routine-only vaccination, overall coverage among WLHIV remained substantially (>50%) lower than in all women for 35-40 years, with gaps persisting even after 80 years. Adding catch-up vaccination for WLHIV aged 15-24 increased coverage and benefits mainly among young WLHIV, with the largest annual reductions (relative to routine-only vaccination) in VT HR-HPV prevalence and CC incidence for WLHIV