Changes in the Rate of Human Papilloma Virus Serotypes after Vaccine Implementation: A Descriptive Study

Background: The main objective of this study is to describe the rate of the different serotypes of HPV in cervical cytologies and biopsies in three different periods: 2002-2006 (prior to the implementation of the vaccination programs in Spain), 2009-2011 (shortly after this implementation) and 2020 (almost 15 years after introduction of the vaccine) at a single hospital. Methods: This is an observational, descriptive, retrospective study based on the review of the results of the determination of the HPV serotype using the commercial kit (Genomica®;PharmaMar LTD) in cervical liquid-based cytologies and biopsies at a single large tertiary hospital, Hospital Clínico San Carlos, in Madrid, Spain. We have collected the data from three different time periods: 2002-2006;2009-2011, and 2020 to try to understand the potential changes associated with the use of the vaccine. Results: In these time periods we have reviewed the data from 1420 women. In the three periods the most frequent serotype was HPV 16, followed by HPV 18 or a combination of both. The most frequent low risk serotype was HPV 6 followed by the combination of HPV 6 and 11. It has been verified in our study that the prevalence of the category “others”, constituted by the three risk groups, has undergone a progressive increase, beginning with an infection rate of 65.43% in 2002-2006 to finally rise up to 90.92% in the year 2020. Conclusions: Our study reveals an increase in the number of infections by the HPV serotypes that are not included in the tetravalent vaccine.

Evolution of Cervical Lesions Associated with Human Papillomavirus Infection after the Introduction of Vaccination

Background: The main objective of this study is to analyse the change in the type of lesions developed by HPV-infected patients after the introduction of the vaccine in three different periods;2002-2006 (years previous to the implementation of the vaccine in Spain), 2009-2011 (shortly after the vaccination) and 2020-2021 (years where the vaccine was well established) at a single hospital. Methods: This is an observational, descriptive, retrospective study based on the review of the results of the biopsies of patients with HPV lesions at a single large tertiary hospital, Hospital Clínico San Carlos, in Madrid, Spain. We have collected the data from three different time periods: 2002-2006, 2009-2011, 2020-2021 to try to understand the potential changes in these lesions after vaccine introduction. Results: In this time we have reviewed the data from 946 women. In these three periods, a decreasing trend in the rate of squamous cell carcinoma was noted, the rate of adenocarcinoma remains stable, and the rate of cervical intraepithelial neoplasia grades 2 - 3 (CIN 2-3) lesions shows an increasing trend. We have also found a change in the mean ages of the patients with these lesions, as this increased in the three lesions caused by HPV after the implementation of the vaccine. Our study indicates that the identification of other high risk serotypes, apart from 16 and 18, as well as those with indeterminate risk, has undergone a progressive increase, increasing from 24.24% and 14.11% respectively in 2002-2006 to 40.42% and 28.34% in 2020-2021. Conclusion: Our study confirms the effectiveness of the vaccines developed so far, against the HPV serotypes they contain. This is demonstrated by the evidence, in our population, of a decrease in the incidence of squamous cell carcinoma in uterine cervix. In parallel, an increase in the mean age of diagnosis has been verified, for both squamous cell carcinoma and its CIN 2-3 precursor lesions, as well as a change in the infective trend of HPV serotypes that are not included in the current vaccines.