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.