Background: The use of human papillomavirus (HPV) vaccines has been universally approved for women from age 12 to 25 years, but those older than 16 years receive no reimbursement for the cost of the vaccine in the Netherlands. Reductions in the vaccine price as well as new insights in the efficacy of HPV vaccines offer renewed arguments to consider HPV vaccination in adult women. We calculated the clinical benefit and cost-effectiveness of vaccinating women aged 17-25 years in 2010.
Methods: The calculations were based on an individual-based simulation model for cervical carcinogenesis, with HPV infection risks obtained from a type-specific HPV transmission model. The indirect protective effect from vaccinating 12 to 16 year-old girls was adjusted for. Cervical screening in the model was incorporated according Dutch screening guidelines, i.e. 7 cytology-based rounds at 5-year intervals from the age of 30. As base-case, we assumed the vaccine to offer full protection against HPV16/18 only if no prior exposure to that type had occurred before vaccination. In sensitivity analyses, we considered partial cross-protection against types 31/33/45/58 and efficacy against all future infections, irrespective of previous or current infection status.
Results: In base-case analyses, vaccinating 17 year-olds reduced their lifetime risk of treatment for precancerous lesions from 7.77% to 3.48% and their lifetime cervical cancer risk from 0.52% to 0.24%. These risks were 6.12% and 0.45%, respectively, for a 25 year-old vaccinee. The incremental cost-effectiveness ratio (ICER) for vaccinating 17-25 year-olds was €22,526 per quality-adjusted life-year (QALY) at a vaccine price of €65 per dose, a 50% reduction of the 2010 pharmacy price in the Netherlands. If cross-protection against types 31/33/45/58 was included, the ICER decreased to €14,734 per QALY. Results were robust to efficacy assumptions with respect to previous or current infection status.
Conclusion: The clinical benefit of HPV vaccination of women up to 25 years moderately depends on cross-protection to non-vaccine types. Refunding the cost of the vaccine to 17-25 year-old women in the Netherlands can be considered cost-effective at anticipated price reductions.
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