In Reply

Letters to the Editor Initial Evidence of a Possible Effect of HPV Vaccination on Cancer Incidence in Germany—Focus on Cervical Cancer by Paula Grieger, Dr. rer. hum. biol. Nora Eisemann, Dr. rer. hum. biol. Friederike Hammersen, Christiane Rudolph, Prof. Dr. med. Alexander Katalinic, and Prof. Dr. rer. nat. Annika Waldmann in issue 13/2024

Dr Hein describes impressively how effective HPV vaccination could be in theory. From comparable areas (for example, cigarette smoking and lung cancer or UV radiation and skin cancer) we know that even if a prevention strategy exists (smoking cessation and sun protection), no success or only very limited success is observed in the short term at the population level, or even that contrary trends prevail (1). Our study, based on cancer registry data, is therefore an initial strong indication that the HPV vaccination strategy in Germany is beginning to be effective at the population level. The fact that we termed the fall in incidence as a “possible effect” of vaccination arises from the principles of evidence based medicine. As an observational study, our study has an only moderate evidence level and does not allow for direct conclusions regarding causality, but it represents the best evidence currently available at the population level in Germany.

We consider it unquestionable that the fall in incidence could be greater if vaccination rates were higher. Similarly, a reduction—such as described by Dr Pauly and Prof. Sievert for the COVID-19 pandemic—or a stagnation in the vaccinate rate can lead to overall worse results in the long term. As described in our article, Drolet et al.’s systematic review confirmed an association between the level of the vaccination rate and the incidence of HPV associated infections (2). Furthermore, the currently available evidence also makes an association between the vaccination rate and the fall in the incidence of cervical cancer seem probable (3). But the fall is not only affected by the vaccination rate but also by other factors—such as the effectiveness of the vaccine used, the organization and target group of the vaccination program, or modified measures in secondary prevention.

In the sense of shared decision making we are in favor of comprehensive education about the benefits and harms of HPV vaccination, which enables an informed decision about whether to be vaccinated. To this end we require quality health information, which in addition to primary prevention (vaccination) also discusses secondary prevention (screening) in an evidence-based manner.

DOI: 10.3238/arztebl.m2024.0209

On behalf of the authors

Prof. Dr. rer. nat. Annika Waldmann

Prof. Dr. med. Alexander Katalinic

Universität zu Lübeck

Institut für Sozialmedizin und Epidemiologie

Conflict of interest statement

The authors declare that no conflict of interest exists.

References

1. Zentrum für Krebsregisterdaten und Gesellschaft der epidemiologischen Krebsregister: Krebs in Deutschland für 2019/2020. Robert Koch-Institut, Berlin, 2023.

2. Drolet M, Bénard É, Perez N, Brisson M, HPV Vaccination Impact Study Group: Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis. Lancet 2019; 394: 497–509.

3. Lin S, Gao K, Gu S, et al.: Worldwide trends in cervical cancer incidence and mortality, with predictions for the next 15 years. Cancer 2021; 127: 4030–9.

4. Grieger P, Eisemann N, Hammersen F, Rudolph C, Katalinic A, Waldmann A: Initial evidence of a possible effect of HPV vaccination on cancer incidence in Germany—focus on cervical cancer. Dtsch Arztebl Int 2024; 121: 415–21.