Cervical Lesions Associated with Human Papillomavirus Infection after Post-Vaccination: An Observational, Descriptive Study

This chapter aims to examine the evolution of lesions caused by HPV infection in patients after vaccination in various time periods, taking into account the years 2002 to 2006 (prior to the vaccine's introduction in Spain), 2009 to 2011 (recent introduction of the vaccination), and 2020 to 2021 (years when the vaccine was widely accepted) at a specific hospital. Human papillomavirus (HPV) is the most prevalent sexually transmitted virus globally. Persistent high-risk HPV infection can result in cervical precancerous lesions and cervical cancer, with 70% of cervical cancer cases associated with high-risk types HPV16 and 18. HPV infection imposes a significant financial and psychological burden. This is an observational, descriptive, retrospective research based on the evaluation of the results of the biopsies of patients lesions related to HPV infection at a large tertiary hospital, Hospital Clínico San Carlos, in Madrid, Spain. The data were taken from three different time periods: 2002-2006, 2009-2011, 2020-2021 in order to understand the potential variations in these lesions after vaccine introduction. The data of 946 women were examined. During these three periods, there was noted a decreasing trend in the rate of squamous cell carcinoma, a stability in the rate of adenocarcinoma remains, and an increasing rate of cervical intraepithelial neoplasia grades 2 - 3 (CIN 2-3) lesions. Another remarkable change founded was the mean ages of the patients with these lesions, as these had increased in the three lesions caused by HPV after the instauration of the vaccine. Our investigation reveals that the recognition of other high risk serotypes, different from classical 16 and 18, as well as those with indeterminate risk, has undergone a progressive increase (from 24.24% and 14.11% respectively in 2002-2006 to 40.42% and 28.34% in 2020-2021). The effectiveness of the vaccines developed so far, against the HPV serotypes they contain has been proved in our investigation. The data shows that the incidence of squamous cell carcinoma in the uterine cervix has decreased in our community. Parallel to this remark, a raise in the mean age of diagnosis for both squamous cell carcinoma and its CIN 2-3 precursor lesions have been established, as has a shift in the infective trend of HPV serotypes not covered in current vaccines.