A new human papillomavirus (HPV) vaccine protects against the 9 HPV types responsible for 90% of cervical cancers and 90% of HPV related anal cancers. It includes the 4 types contained in the quadrivalent (HPV 6,11,16,18) and 5 additional high-risk oncogenic HPV types (HPV 31, 33, 45, 52, 58). This analysis aims to estimate the public health impact and the incremental cost-effectiveness of a universal (girls and boys) vaccination program with a nonavalent HPV vaccine as compared to a girls only (S1) or universal (S2) vaccination program with a quadrivalent HPV vaccine in Italy.
A dynamic transmission model including health and cost outcomes related to cervical, anal, vulvar, vaginal diseases and genital warts was calibrated to Italian epidemiological data. The clinical impact due to the 5 new types was included for cervical and anal diseases only. In the base case, a two-dose schedule, lifelong vaccine protection and a vaccination coverage rate of 71% for the 12-year old cohorts were assumed. Ex-factory price of €104 for the quadrivalent vaccine and a theoretical price of €120 for the nonavalent vaccine (corresponding to the public price in the US) were assumed. A threshold of 30,000€/QALY-gained was considered. Deterministic sensitivity analyses on key parameters (such as vaccine price, duration of protection, discount rate) were conducted. No cross protection was considered for the strategies using the quadrivalent vaccine.
Over 100 years, the implementation of a universal vaccination programme with a nonavalent vaccine could avert 22.640 cervical cancers, 275.717 CINs, 8.111 anal cancers and 1.866.845 genital warts compared to S1. This would correspond to decrease with S1 the vaccine-type related incidence of cervical cancer and precancerous lesions by 81% vs 63%, of anal cancer, by 82% in females vs 68% and 77% vs 42% in males, of genital warts by 55% vs 48% in females and 44% vs 21% with S1 in males and 66%, 75%, 71%, 55% and 44% respectively with S2. The ICER of the switch to a nonavalent universal vaccination was estimated to be equal to 7.165€/QALY when compared to S1 and 10.478€/QALY when compared to S2
The switch to a universal vaccination programme with a nonavalent vaccine in Italy is estimated to be highly cost-effective across a range of sensitivity analyses and is expected to further reduce the public health burden of HPV-related cancers and diseases compared to the current vaccination program.