Projected health and economic effects of nonavalent versus bivalent human papillomavirus vaccination in preadolescence in the Netherlands

Abstract

BackgroundThe national immunization program in the Netherlands currently uses the bivalent human papillomavirus (HPV) vaccine, targeting HPV genotypes 16 and 18. It is not yet clear whether it is cost-effective to switch to the nonavalent vaccine, targeting an additional seven HPV genotypes. This study compares the health and economic effects of both vaccines for the Dutch setting of sex-neutral vaccination with tender-based procurement and HPV-based screening for cervical cancer.MethodsWe estimated the population effects under bivalent or nonavalent HPV vaccination in a cohort of girls and boys, invited for vaccination at 10 years of age. The differential impact of nonavalent versus bivalent HPV vaccination was obtained by projecting type-specific risk reductions, obtained by an HPV transmission model, onto type-specific outcomes of HPV-based screening, incidence of HPV-related cancers in both men and women, as well as treatment for anogenital warts and recurrent respiratory papillomatosis. Bayesian analysis was applied to translate the uncertainty of the data into credible intervals (CI) for health and economic outcomes, under specific scenarios regarding long-term vaccine uptake, efficacy and cost. The base-case scenario assumed 50% uptake at age 10, life-long vaccine protection with cross-protective efficacy to HPV 31, 33 and 45 from the bivalent vaccine, and an additional cost of EUR 35 per 2-dose vaccination schedule for the nonavalent vaccine.ResultsIn the base-case scenario, nonavalent vaccination is expected to prevent 1090 additional cases of high-grade cervical intraepithelial neoplasia (CIN2/3), 70 additional cases of HPV-related cancer, 34 000 episodes of anogenital warts and 28 onsets of RRP, relative to bivalent vaccination per cohort of 100 000 girls and 100 000 boys. These health effects translate into an incremental cost-effectiveness ratio (ICER) of EUR 2048 (95% CI: 716 to 3141) per life-year gained, under annual discounting of 1.5% and 4% for future health and economic effects, respectively. The ICER remained below the local threshold for cost-effective preventive interventions in all investigated scenarios, except when assuming waning efficacy for non-16/18 oncogenic HPV types with either vaccine or cross-protection to non-31/33/45 types for the bivalent vaccine.ConclusionsSex-neutral vaccination with the nonavalent vaccine is likely to be cost-effective relative to the currently used bivalent vaccine in the Netherlands. Monitoring long-term type-specific vaccine effectiveness is key to update projections on the impact and cost-effectiveness of HPV vaccination.