Danish HPV Vaccination Success: Types 16 and 18 Nearly Eliminated

In a significant public health development, a recent study has revealed that types 16 and 18 of the human papillomavirus (HPV) have been nearly eradicated among vaccinated women in Denmark. This finding comes as part of ongoing research into the efficacy of the HPV vaccination program introduced in the country since 2008. According to the European Centre for Disease Prevention and Control (ECDC), HPV types 16 and 18 are responsible for approximately 74% of cervical cancer cases, highlighting the importance of the vaccination in preventing this disease.

The study, published in the journal *Eurosurveillance* by a team led by Dr. Mette H. Nonboe from the University of Copenhagen, analyzed cervical samples from 17,252 women aged 22 to 30 years from February 2017 to February 2024. The results indicated that the prevalence of HPV16 and HPV18 among vaccinated women dropped from 15-17% pre-vaccination to less than 1% by 2021. Conversely, unvaccinated women showed a prevalence of 5% for these types, suggesting a strong indication of population immunity among the vaccinated cohort.

Despite this positive outcome, the research also uncovered a concerning trend: one-third of the women screened during the study were infected with other high-risk HPV types not covered by the vaccines. Notably, the incidence of these non-vaccine types was higher among vaccinated women compared to their unvaccinated counterparts. This raises questions about the potential need for continued cervical cancer screening and the effectiveness of current vaccination strategies against these other high-risk types.

Dr. Nonboe and her colleagues recommend a re-evaluation of cervical screening protocols, particularly as more women vaccinated with the current 9-valent vaccine reach the screening age of 23. They suggest that less intensive screening may be justified until this cohort is fully integrated into the screening program.

The implications of this study extend beyond Denmark, as it provides valuable insights into the long-term effectiveness of HPV vaccines and their role in cervical cancer prevention. Experts such as Dr. Sarah Johnson, a Professor of Epidemiology at Harvard University, note that while the elimination of HPV types 16 and 18 is a significant achievement, the persistence of other high-risk types underscores the necessity for ongoing research and adaptation of public health strategies.

Additionally, the World Health Organization (WHO) emphasizes that comprehensive vaccination and screening programs are essential for reducing the global burden of cervical cancer, which remains a leading cause of cancer-related mortality among women worldwide.

In summary, while the Danish HPV vaccination program has shown remarkable success in reducing the prevalence of HPV types 16 and 18, health authorities must remain vigilant to address the challenges posed by other high-risk HPV types. Continued research, adaptive screening strategies, and public awareness campaigns will be crucial in the fight against cervical cancer and the broader implications of HPV on women's health.