Objectives: The cost-effectiveness of adding a human papillomavirus (HPV) vaccination program in 12-year-old females to the recommended cervical cancer screening in Belgium is examined. Moreover, the health and economic consequences of a potential decline in screening uptake after initiation of a HPV vaccination program are investigated.

Methods: A static Markov model is developed to estimate the direct effect of vaccination on precancerous lesions and cervical cancers.

Results: Vaccination is estimated to avoid 20 percent of the cervical cancers occurring in a 12-year-old girls' cohort and to cost €32,665 per quality-adjusted life-year (QALY) gained (95 percent credibility interval [CrI]: €17,447 to €68,078), assuming a booster injection after 10 years, a limited duration of protection and discounting costs and effects at 3 percent and 1.5 percent, respectively. Assuming lifelong protection, HPV vaccination is estimated to cost €14,382 (95 percent CrI: €9,238 to €25,644) per QALY gained, while avoiding 50 percent of the cervical cancer cases. In the base-case, a 10 percent reduction in screening compliance after vaccination obliterates the effect of vaccination on cervical cancer cases avoided, whereas further declines in the level of screening compliance even turned out to be detrimental for the cohort's health, inducing a mean loss in QALYs and life-year gained compared with the situation prevaccination.

Conclusions: An HPV vaccination program should only be considered if the level of screening after vaccination can be maintained.