The study, published as Extended follow-up of invasive cervical cancer risk after quadrivalent HPV vaccination: nationwide, register based study, confirms findings and notes publication with a 2026 date and DOI 10.1136/bmj-2025-087326.

Vaccination status showed that 40% of participants received at least one HPV vaccine dose during follow-up, totaling 365,502 vaccinated individuals and 930 invasive cervical cancer cases (97 in vaccinated vs 833 in unvaccinated).

Researchers controlled for socioeconomic and demographic factors and performed sensitivity analyses, supporting robustness despite the observational design.

Limitations include potential misclassification and unmeasured lifestyle factors like smoking and sexual behavior, inherent to observational studies, though findings align with immunological data on durable memory.

Additional limitations noted include possible healthy volunteer bias and unmeasured factors such as smoking and sexual activity.

Collaborators include the Public Health Agency of Sweden and Karolinska University Hospital; funding came from multiple Swedish and EU sources, with no conflicts of interest reported.

No signs of waning protection were observed during follow-up, regardless of vaccination timing, suggesting no current need for booster doses.

Overall, protection remained strong over 18 years with substantial long-term risk reductions among the vaccinated.

The study acknowledges lack of data on lifestyle/sexual behavior and HPV type in cancers but leverages large-scale real-world registry data with long follow-up.

A Swedish nationwide study followed 926,362 women born from 1985 to 2001 to evaluate long-term protection from the quadrivalent HPV vaccine against invasive cervical cancer over 18 years (2006–2023).

Further collaboration and funding came from the Public Health Agency of Sweden, Karolinska Institutet, and various Swedish and EU research funders; researchers report no competing interests.

Results support early vaccination of pre-adolescents and indicate no need for booster doses in the general population, reinforcing global cervical cancer elimination goals.