Evaluation of the Therapeutic Effect of Quadrivalent Human Papillomavirus (HPV) Vaccination on Cervical Intraepithelial Neoplasia Lesions.

Cervical cancer is the most common health problem among global young women. Cervical intraepithelial neoplasia (CIN) is a pre-invasive stage of cervical cancer, the major cause of which is human papillomavirus (HPV), and vaccination has a promising effect on reducing the progression of CIN lesions. The current study was a retrospective case control investigation in two centers, Shiraz and Sari Universities of Medical Sciences from 2018 to 2020 to evaluate the effect of quadrivalent HPV vaccination on CIN lesions (I, II, and III). Eligible patients diagnosed with CIN were selected and divided into two groups: one group received HPV vaccine and the control group did not. The patients were followed up after 12 and 24 months. The information about tests (e.g., Pap smear, colposcopy, and pathology biopsy) and history of vaccination was recorded and statistically analyzed. 150 patients were classified into the control group (without HPV vaccination) and the other 150 patients were in the Gardasil group (with HPV vaccination). The patients' mean age was 32 years old. Two groups were not significantly different according to age and CIN grades. Between two groups in 1 and 2 years' follow-up examinations, the high-grade lesions in both Pap smear and pathology were significantly diminished in patients in the HPV vaccinated group in comparison with the control group with -values 0.001 and 0.004 in 1 year follow-up respectively and 0.00 after 2 years follow-up. HPV vaccination can prevent the progression of CIN lesions in 2-year follow-up examination.