Background
Cervical cancer remains a major oncological challenge in Kazakhstan, with an incidence rate of 18.9 and mortality of 5.7 per 100,000 women. Despite national screening programs, disease burden remains high. Following a pilot HPV vaccination program (2013–2015) using bivalent and quadrivalent vaccines, this study evaluated the long-term effectiveness of HPV vaccination in reducing HPV infection and precancerous cervical lesions.

Methodology
A cross-sectional and retrospective study was conducted from 2014 to 2023 including 1,920 women aged 18–30 years: 1,120 vaccinated with HPV vaccine and 800 unvaccinated controls. All participants underwent PCR testing for HPV DNA and cytological screening (Pap smear). Epidemiological trends were assessed using national registry data, and intergroup comparisons were performed with χ² and logistic regression analysis.

Results
Among 1,920 women (1,120 vaccinated; 800 unvaccinated), high-risk HPV 16/18 infection was detected in 6.8% of vaccinated and 22.4% of unvaccinated participants (p<0.001). Cytological abnormalities (ASC-US, LSIL, HSIL) occurred in 4.5% and 14.2%, respectively (p=0.002). Vaccinated women showed a 3.3-fold lower risk of high-risk HPV infection (OR 0.30, 95% CI 0.18–0.49). Over 2014–2023, national cervical-cancer incidence decreased from 19.8 to 16.1 per 100,000 and mortality by 11%. Awareness of HPV vaccination increased from 27% to 42% among respondents, but parental hesitancy remained a key barrier. These results confirm sustained vaccine effectiveness and underscore the need for nationwide immunization expansion.
 
Conclusions
HPV vaccination significantly decreases high-risk HPV infection and cytological abnormalities among young women in Kazakhstan. These findings strongly support nationwide implementation of HPV vaccination.