Human papillomavirus (HPV) is considered the most common sexually transmitted agent worldwide and more than 100 types of HPV have been identified. Persistent infection with oncogenic HPV is recognized as a necessary cause of cervical cancer. Approximately 70% of cervical cancers in the world are attributed to two of the most common HPV types, 16 and 18.

This systematic review was carried out to assess whether the HPV vaccines currently offered to 11 to 12 year-old girls in Norway are also effective as a catch-up vaccination for women up to age 26 in preventing HPV-related diseases.

For HPV vaccination of women aged 16 and older:

• The results show a protective effect of HPV vaccination against Cervical intraepithelial neoplasia grade 2 and higher (CIN2+) associated with the HPV types included in the vaccines (high quality of the evidence), and indicate a protective effect against all CIN2+ lesions (independent of HPV types in the lesions) (moderate quality of evidence).
• The quadrivalent HPV vaccine protects against genital warts (high quality evidence).
• Long-term (up to 8 years) follow-up after HPV vaccination indicates little or no difference in the occurrence of serious adverse events when compared to the control groups (moderate quality of evidence).