Years of the cervical cancer vaccine in Brazil: what has changed, what can improve, and what are the prospects for the future

Introduction: Human papillomavirus (HPV) is the most common sexually transmitted infection worldwide. Lesions caused by some HPV subtypes increase the likelihood of cervical neoplasia. In 2023, the forecast was for 17,010 new cases, representing a rate of 13.25 cases per 100,000 Brazilian women. This article proposes a review of the literature and the collection of statistical data from the DataSUS System (Department of Informatics of the Unified Health System) to perform an epidemiological analysis of HPV-induced lesions after the ten-year anniversary of the implementation of the quadrivalent vaccine in primary care.

Methodology: The study is classified as a retrospective ecological study and employs a time-series and census approach, covering the period between 2013 and 2024. Quantitative variables were tabulated and presented as absolute data; when necessary, percentages were also calculated using the same program. Additionally, a non-systematic literature review was conducted to investigate the effects of HPV vaccination in Brazil and other countries.

Results: The results show that HPV vaccination has reduced genital warts by 90%. Another point observed from the collected data was a significant increase in cervical lesion screening in Brazil; the number of cytopathological exams performed increased by 5663% between 2013 and 2023. This increase was accompanied by a rise in the detection of adenocarcinoma in situ and high-grade pre-neoplastic lesions. However, since the vaccinated population has not yet reached the peak age for incidence (i.e., between 30 and 50 years), the full impact of the vaccination is not yet entirely visible. Additionally, a meta-analysis of seven studies conducted worldwide on the prevalence of HPV found a 68% reduction in HPV types 16 and 18 infections in countries with at least 50% vaccination coverage.

Conclusion: HPV vaccination has demonstrated a significant reduction in infections with types 16 and 18, with a decrease in cervical lesions in countries with high vaccination coverage. In Brazil, the increase in the number of cytopathological exams reflects greater screening and detection of early lesions, although a complete assessment of the impact of vaccination on cervical lesions still requires more time and additional studies.

Corresponding author: Gustavo Drummond Pinho Ribeiro (e-mail: gdrummond95@gmail.com).