Cervical Pathology Following HPV Vaccination in Greece: A 10-year HeCPA Observational Cohort Study.

BACKGROUND: In Greece the population-level impact of HPV vaccination is unknown due to lack of official registries. This study presents in a pragmatic frame the comparison of cervical pathology data between HPV-vaccinated and unvaccinated women referred for colposcopy. PATIENTS AND METHODS: This is an observational prospective cohort study performed in 7 academic Obstetrics and Gynaecology Departments across Greece between 2009-2019. Cases were women that had completed HPV vaccination before coitarche and were referred for colposcopy due to abnormal cytology. For each vaccinated woman an unvaccinated matched control was selected. RESULTS: A total of 849 women who had been vaccinated before coitarche and 849 unvaccinated controls were recruited. The combination of cytological, colposcopic and molecular findings necessitated treatment in only a single case among vaccinated (0.1%) and in 8.4% among unvaccinated. CONCLUSION: HPV vaccination at a proper age can markedly reduce development of severe cervical precancers and consequently the need for treatment, as well as their long-term related obstetrical morbidity.