Human papilloma virus (HPV) prevalence upon HPV vaccination in Swedish youth: a review based on our findings 2008–2018, and perspectives on cancer prevention

Abstract

Abstract Purpose Three human papillomavirus (HPV) vaccines are available against up to nine HPV types. In Sweden, from 2012, Gardasil was offered to 10−12 year old girls through the school-based vaccination program, and as catchup vaccination for women up to 26 years. To obtain a baseline, and follow HPV vaccination effects, during 2008−2018, cervical and oral HPV prevalence were followed at a youth clinic in Stockholm, and in 2013 for comparison oral HPV prevalence was examined in high-school youth in a middle-sized county in Sweden. Methods In this review, we discuss all our data with cervical and oral mouthwash samples that were collected and tested for 24−27 HPV types by a bead-based multiplex assay from 2008. Results Compared with 2008−2011, with ~ 35% HPV16 and > 60% high risk (HR) HPV cervical prevalence at the youth clinic, a decrease of vaccine HPV types was observed between 2013 and 2018, with e.g., HPV16 falling to 5% in catchup vaccinated women and 15−18% in nonvaccinated women. Most common cervical HR-HPV types were HPV39, 51, 52, 56, and 59 together accounting for ~ 10% of cervical cancer, and where only HPV52 is included in Gardasil-9. At baseline 2009−2011, oral HPV prevalence was ~ 10% in unvaccinated youth at the youth clinic, but after 2013 it dropped to < 2% at the youth clinic and high schools. Conclusion To conclude, Gardasil HPV types have decreased, but it is still important to follow remaining HR-HPV types and cancer development, since there is an ongoing increase in the incidence of HPV-associated tonsillar and base of tongue cancer, and cervical cancer in Sweden.