Long-term HPV vaccine effectiveness study shows stable protection against targeted virus types in Danish women vaccinated as girls

Summary

This study examines the long-term effectiveness of HPV vaccination in Danish women who received the 4-valent HPV vaccine as girls in 2008. The research followed 8,659 women over 7 years (2017-2024) through the Trial23 cohort study, analyzing cervical cell samples for HPV16/18 and non-vaccine high-risk HPV types. Results show extremely low prevalence of vaccine-targeted HPV16/18 (0.4% in first sample, decreasing to 0.2% in third sample) but higher prevalence of non-vaccine HPV types (32% in first sample). Vaccinated women had significantly lower incidence of HPV16/18 infections compared to unvaccinated women, while showing higher incidence of non-vaccine HPV types. The study provides real-world evidence supporting stable protection against vaccine-targeted HPV types and suggests less intensive screening may be reasonable until women vaccinated with newer 9-valent vaccines reach screening age.