Peer-reviewed article
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.
Carla M Doyle, Minttu M Rönn, Cari van Schalkwyk, Marc Brisson, Nirali Soni et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study uses mathematical models to predict how catch-up HPV vaccination for women living with HIV in South Africa could reduce cervical cancer risk. The research compares routine vaccination of girls aged 9-14 alone against adding catch-up vaccination for adult women living with HIV. Results show that catch-up vaccination could prevent a significant portion of cervical cancer cases, particularly if offered to women of all ages rather than only younger women.
Key points
- Routine-only vaccination of girls leaves over 50% of women living with HIV unvaccinated for 35-40 years
- Catch-up vaccination of women living with HIV aged 15-24 reduced vaccine-type HPV prevalence by 36%-52% and cervical cancer incidence by 38%-100% within 15 years for those under 30
- Expanding catch-up vaccination to all women living with HIV aged ≥15 could avert up to 14% of cervical cancer cases over 55-60 years, compared to 3%-8% for younger women only
- Offering vaccines to women living with HIV of all ages rather than only younger women could shift peak benefits 25 years earlier and provide an additional 19% reduction in cervical cancer incidence for women aged 50+
- Catch-up vaccination benefits are demonstrated even when routine girls-only vaccination achieves 90% cohort coverage
Limitations
This is a modelling study using mathematical predictions, not empirical data from actual vaccination programmes. The models assume lifelong 100% vaccine protection and do not assess real-world implementation challenges, vaccine acceptance rates among women living with HIV, or cost-effectiveness.
Abstract
INTRODUCTION: Women living with HIV (WLHIV) face an increased risk of cervical cancer (CC). With inequitable human papillomavirus (HPV) vaccine access globally and a programmatic focus on girls-only school-based delivery, many WLHIV in high HIV prevalence countries remain vulnerable to HPV 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 onwards using a nonavalent vaccine (lifelong 100% protection). We assessed catch-up scenarios vaccinating WLHIV aged 15-24 or ≥15 (attaining 90% cohort coverage), 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 cases averted compared to routine-only vaccination among WLHIV overall (age-standardized) and by age. RESULTS: With routine-only vaccination, overall coverage among all 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 <30 years, reaching up to 36%-52% across models within 15 years and 38%-100% after 15-25 years, respectively. If catch-up included WLHIV aged ≥15, overall vaccination coverage among WLHIV would immediately increase to 90%, extending benefits to older WLHIV-reducing peak annual relative reductions in CC incidence among WLHIV ≥50 by an extra 19% points compared to catch-up vaccination of WLHIV aged 15-24, and shifting the peak 25 years earlier. Over 55-60 years, catch-up vaccination of WLHIV aged 15-24 and ≥15 could avert up to 3%-8% and 14% of CC cases among WLHIV, respectively. CONCLUSIONS: Catch-up vaccination of WLHIV can reduce their CC burden in the short to medium term, even in the presence of girls-only routine vaccination programmes with high cohort coverage. To maximize impact, vaccines should be offered to WLHIV of all ages, not only younger women.