Post-Conization HPV Vaccination and Its Impact on Viral Status: A Retrospective Cohort Study in Troms and Finnmark, 2022.

Human papillomavirus (HPV) is associated with cellular changes in the cervix leading to cancer, which highlights the importance of vaccination in preventing HPV infections and subsequent cellular changes. Women undergoing the loop electrosurgical excision procedure (LEEP), a treatment for high-grade cervical intraepithelial neoplasia (CIN2+), remain at risk of recurrence. This study assessed the effect of post-conization HPV vaccination on the viral status of women at six months post-conization, aiming to evaluate the vaccine's effectiveness in preventing recurrence of CIN2+. A retrospective cohort study was conducted among women in Troms and Finnmark who underwent conization in 2022. Using the SymPathy database and the national vaccination register (SYSVAK), we analyzed the vaccination statuses and HPV test results of women born before 1991, who had not received the HPV vaccine prior to conization. Out of 419 women undergoing conization, 243 met the inclusion criteria. A significant association was found between post-conization HPV vaccination and a negative HPV test at six months of follow-up (ARR = 12.1%, p = 0.039). Post-conization HPV vaccination significantly reduced the risk of a positive HPV test at the first follow-up, suggesting its potential in preventing the recurrence of high-grade cellular changes. However, the retrospective design and the insufficient control of confounding variables in this study underscore the need for further studies to confirm these findings.