Cost-effectiveness and epidemiological impact of gender-neutral HPV vaccination in Spain

All EU countries have introduced Human papilloma virus (HPV) vaccination for adolescent girls and many countries are expanding the strategy to include adolescent boys. There is uncertainty about the cost-effectiveness and epidemiological impact of a gender-neutral HPV vaccination strategy. Here we present the results of an economic model adapted for Spain. Five vaccination strategies were compared from the Spanish healthcare system perspective, combining two vaccines (4-valent and 9-valent) in a gender-neutral or girls-only programme in a dynamic population-based model with a discrete-time Markov approach. Costs and benefits were discounted at 3%. The benefits of immunization were measured with quality-adjusted life years (QALYs), which are achieved by reducing the incidence of diseases attributable to HPV. Incremental cost-effectiveness ratio (ICER) was compared with the willingness-to-pay threshold in Spain. The two most effective strategies were compared: gender-neutral 9-valent vaccination vs. girls-only 9-valent vaccination, resulting in an ICER of euro 34,040/QALY, and an important number of prevented cases of invasive cancers and anogenital warts. The sensitivity analysis revealed that gender-neutral 9-valent vaccination would become cost-effective if protection against oropharyngeal and penile cancers was included or if the price per dose decreased from euro45 to euro28. The gender-neutral 9-valent HPV vaccination in Spain offers more benefits than any other modeled strategy, although in the conservative base case it is not cost-effective. However, certain plausible assumptions would turn it into an efficient strategy, which should be borne in mind by the decision makers together with equity and justice arguments. Plain Language Summary What is the context? Human papillomavirus (HPV) is a group of viruses that causes sexually transmitted diseases, including certain cancers. European countries offer HPV vaccination to adolescent girls. Many countries have also introduced the vaccination in adolescent boys. There are doubts about whether it is worth vaccinating adolescents of both genders. What this study adds? We estimated costs and benefits of the vaccination in Spain, comparing two types of vaccine, only in girls and in both genders. This analysis considered indirect protection of vaccinated people to unvaccinated ones. It seems that the benefits of HPV vaccination in all adolescents do not compensate the costs. However, when we included likely protection against additional cancers or we reduced the price per vaccine dose, it would be worth vaccinating all adolescents in Spain. We also stated ethical arguments in favor of HPV vaccination for both genders. What is the impact? HPV vaccination in adolescent boys and girls in Spain will prevent more HPV-related diseases. For certain scenarios, HPV vaccination in both genders would be worth in Spain. Ethically, vaccinating also boys would be fair, equitable and would not discriminate a part of the population.