Background: A next generation nonavalent vaccine (HPV9; Gardasil-9) is being introduced in several countries. The lifetime risk of cervical cancer in cohorts offered this vaccine will be substantially reduced but it is not known whether cervical screening in these cohorts will remain cost-effective. Models can be used to characterize the outcomes from progressively less intensive screening strategies and thus inform determination of the optimal number of cervical cancer screening tests in a woman’s lifetime for individuals or cohorts offered HPV9.
Objective: To evaluate whether cervical screening will remain cost-effective in cohorts offered nonavalent vaccines and if so, to characterize the optimal number of screening tests.
We performed a modelled evaluation using a dynamic model of HPV vaccination and cervical screening for four countries – the USA, New Zealand (NZ), Australia and England. For each country, we considered local factors including vaccine uptake rates (USA/NZ uptake ~50%; Australia/England uptake >70%);, attributable fractions of HPV9-included types, demographic factors, costs and indicative willingness-to-pay (WTP) thresholds. The most cost-effective screening strategy was assessed for cohorts offered HPV9.
In the USA, four screens per lifetime was the most cost-effective option, with a 34% probability of being the optimal strategy at WTP US$50,000/LYS, and 84% probability at US$100,000/LYS. In New Zealand, five screens was the most cost-effective, with 100% probability of being optimal at NZ$42,000/LYS. In Australia, two screens was the most cost-effective option, with 62% probability of being optimal at AU$50,000/LYS. In England, four screens was the most cost-effective option, with 32% probability of being optimal at WTP of GB£20,000/QALY, increasing to 92% probability at GB£30,000/QALY
Some form of cervical screening is still likely to be cost-effective in cohorts of young females offered the nonavalent vaccine, even in countries with high vaccine uptake, but the optimal number of lifetime screens varies by country.