HPV Vaccination and the Decline of High-Grade Cervical Intraepithelial Neoplasia: A Global Population-Based Cohort Analysis with Projections for Pakistan

Abstract

Cervical cancer, largely driven by persistent infection with high-risk human papillomavirus (HPV) types, remains a significant global health challenge, especially in low- and middle-income countries (LMICs). High-grade cervical intraepithelial neoplasia (CIN2/3) is the most critical pre-malignant lesion leading to cervical cancer. Since the introduction of HPV vaccines in 2006, multiple high-income countries have reported substantial reductions in both HPV infection rates and CIN2/3 incidence. This study synthesizes longitudinal population-based cohort studies from 2006 to 2025 to quantify global declines in CIN2/3 and model potential trajectories for countries such as Pakistan that are beginning national HPV vaccination efforts. Findings reveal that early, widespread, and school-based vaccine delivery in countries like the UK and Australia resulted in CIN2/3 incidence reductions of 75–88%, while late adopters and LMICs show slower progress. For Pakistan, projections estimate a 25–40% reduction in CIN2/3 by 2040 with appropriate scale-up. This paper underscores the imperative to integrate HPV vaccination with national screening and public health strategies, emphasizing policy, education, and healthcare infrastructure reforms for sustained cervical cancer prevention.