Cost-effectiveness of the next generation nonavalent human papillomavirus vaccine in the context of primary human papillomavirus screening in Australia: a comparative modelling analysis

Background First generation bivalent and quadrivalent human papillomavirus (HPV) vaccines have been introduced in most developed countries. A next generation nonavalent vaccine (HPV9) has become available, just as many countries are considering transitioning from cytology-based to HPV-based cervical screening. A key driver for the cost-effectiveness of HPV9 will be a reduction in screen-detected abnormalities and surveillance tests. We aimed to evaluate the cost-effectiveness of HPV9 in Australia, a country with HPV vaccination of both sexes that is transitioning to 5-yearly HPV-based screening. Methods We used Policy1-Cervix and HPV-ADVISE-two dynamic models of HPV transmission, vaccination, and cervical screening-to estimate the cost-effectiveness of HPV9 versus quadrivalent vaccine (HPV4), assuming lifelong vaccine protection, two vaccine doses, and that additional costs were incurred in girls only. Policy1-Cervix was used to estimate the lifetime risk of cervical cancer diagnosis and death. Probabilistic sensitivity analysis of the cost-effectiveness outcomes was done with both models, and results are presented as the median and 10th to 90th percentiles of simulation runs (referred to as 80% uncertainty intervals [UIs]). Findings Compared with cytology-based screening, HPV screening is predicted to reduce lifetime risk of cervical cancer diagnosis by 18% and of death by 20%, even in unvaccinated cohorts. Under base-case assumptions (lifelong protection, full efficacy at two doses), HPV4 will provide a further reduction in diagnosis of 54% and in death of 53% and HPV9 will provide a further reduction in both diagnosis and death of 11%, compared with cytology-based screening in unvaccinated cohorts. For HPV9 to remain a cost-effective alternative to HPV4, the incremental cost per dose in girls should not exceed a median of AUS$35.99 (80% UI 28.47-41.18) with Policy1-Cervix or AUS$22.74 (15.49-34.45) with HPV-ADVISE, at a willingness-to-pay threshold of AUS$30 000 per quality-adjusted life-year. Interpretation Differing methods and assumptions led to some differences in the estimates produced by the two models. However, on the basis of median results, HPV9 will be a cost-effective alternative to HPV4 if the additional cost per dose is AUS$23-36 (US$18-28). These results will be important when determining the optimum price of the vaccine in Australia. Copyright (C) The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND license.