Impact and cost-effectiveness of nonavalent human papillomavirus vaccination in Switzerland: insights from a dynamic transmission model

AIM: In Switzerland, human papillomavirus (HPV) vaccination has been implemented using a quadrivalent vaccine that covers HPV types 16 and 18, responsible for about 70% of cervical cancer. The average national uptake was 56% in girls by the age of 16 years in 2014-2016. A nonavalent vaccine, covering five additional oncogenic HPV types was recommended at the end of 2018. The primary aim of this study was to assess the impact and cost-effectiveness of introducing the nonavalent HPV vaccine in Switzerland compared with the quadrivalent vaccine. METHODS: We developed a dynamic transmission model that describes the spread of 10 high risk HPV types. We informed the model with Swiss data about sexual behaviour and cervical cancer screening, and calibrated the model to cervical cancer incidence in Switzerland. We modelled the impact of quadrivalent and nonavalent vaccines at the achieved (56%) and national recommended uptake (80%) in girls. We calculated the incremental cost-effectiveness ratio (ICER) between the nonavalent vaccine, the quadrivalent vaccine and no vaccination. We evaluated costs linked to cervical cancer screening, treatment of different disease stages and vaccination in a sensitivity analysis. RESULTS: Compared with quadrivalent HPV vaccination in Switzerland at 56% uptake, vaccinating with the nonavalent vaccine would avert 1,175 cervical cancer deaths, 3,641 cases of cervical cancer and 106,898 CIN treatments over 100 years at 56% uptake. Compared with the quadrivalent vaccine, which would prevent an estimated 67% and 72% of cervical cancer cases at 56% and 80% coverage, the nonavalent vaccine would prevent 83% and 89% of all cervical cancers at the same coverage rates. The sensitivity analysis shows that introducing the nonavalent vaccination should improve health outcomes and offers a cost-saving alternative to the quadrivalent vaccine under the current price difference. CONCLUSIONS: All scenarios with quadrivalent and nonavalent vaccination are likely to be cost-effective compared with no vaccination. Switching to the nonavalent vaccine at current and improved vaccination uptake is likely to be cost-saving under the investigated price difference.