Impact of Multicohort Human Papillomavirus Vaccination on Cervical Cancer in Women Below 30 Years of Age: Lessons Learned From the Scandinavian Countries.

In Scandinavia, human papillomavirus (HPV) vaccination programs started in 2007-2008 in Sweden and Denmark with HPV vaccination offered to multiple cohorts of young girls, while in Norway this was offered to a single cohort only. Interestingly, in Sweden and Denmark, cervical cancer incidence in young women decreased markedly from 2017 to 2018, while in Norway a steady increase was seen until 2020. As the 3 countries are very similar in other factors important for cervical cancer incidence rates, like cervical cancer screening, the observed difference is most likely due to differences in the multicohort vaccination.