Estimating the long-term effects of HPV vaccination in Germany

• First dynamic mathematical model evaluating and comparing the impact of the bivalent and the quadrivalent HPV vaccines in Germany.
• Extensive calibration to German epidemiologic data.
• Reproduction of screening modalities in Germany in great detail.
• Decline in mortality of cervical cancer due to increased screening lasts until 2030.
• Decline due to vaccination starts in 15 years and reach saturation in 60 years.

In Germany, vaccination against the most oncogenic HPV types 16/18 is recommended by the Standing Committee on Vaccination (STIKO) for 12–17 year old girls since March 2007. We developed a dynamic mathematical model for the natural history and transmission of HPV infections to estimate the impact of vaccination on incidence and mortality of cervical cancer and its pre-stages, and on anogenital warts. We focused on an extensive model calibration to epidemiologic data for all stages of the natural history model as well as on a detailed implementation of cervical cancer screening modalities in Germany. Our model predicts first a substantial reduction of cervical cancer incidence and mortality over the next 30 years, which is mainly attributable to an increase in screening participation in the 1990s and not to HPV vaccination, followed by a further reduction attributable to vaccination. Over the next 100 years, HPV vaccination will prevent approximately 37% of cervical cancer cases even if vaccination coverage is only 50% (as currently observed in Germany). Consideration of cross-protection results in a further reduction of approximately 7% of all cervical cancer cases for the bivalent and about 5% for the quadrivalent vaccine in our model. Vaccination of boys was only reasonable if moderate to high vaccination coverage in girls was not achieved. Strategies should be implemented in Germany to increase HPV vaccination coverage among girls thereby making better use of the demonstrated benefits of the vaccine.