Effects of HPV-vaccination in Norway

The project monitors the incidence of pre-stages to cancer and cancer of the cervix, vulva and vagina among Norwegian women in the period 2004-2023 to investigate any effects of HPV vaccination.

Background and aim

The aim of the project is to investigate the effect of HPV vaccination in Norway on pre-stages to cancer and cervical cancer. HPV vaccine that protects against the HPV types that cause most cases of pre-stages to cancer and cervical cancer has been available since 2007. Birth cohorts with a high coverage rate of the vaccine are approaching the age at which pre-stages to cancer and cervical cancer can occur. We will investigate whether HPV vaccination begins to have a protective effect in the population. This is very important knowledge from a public health perspective. The study focuses on the vaccine type Gardasil, which was given in the childhood vaccination program in the period 2009-2016.

In addition, we will monitor the incidence of pre-stages to cancer and cancer of the vulva and vagina, as these also are related to HPV-infection.

Data material

This is a register-based study at the population level. All information used in the study is routinely collected by public health registries, and the study therefore does not require active participation from the women included in the study.

The total study population is all women living in Norway as of January 1^st in each calendar year 2004-2023. Information about dates and results from cell samples, diagnostics and treatment is collected from the Cancer Registry. The Norwegian Prescription Database and the National Vaccination Registry (SYSVAK) collect data related to HPV vaccination, such as when the vaccine was prescribed/taken and which vaccine was involved. MSIS collects information about any diagnoses of sexually transmitted infections. The social security number makes it possible to collect and link data between the registries.

The project data received from each registry will be pseudonymized, i.e. without a name, social security number etc., which makes it impossible to directly identify individuals. The data file will only contain the minimum number of variables needed to address the aim of the study, and date variables will not be more accurate than month and year. This minimizes the chance of so-called indirect identification. Results from the study will be presented at the overall level. The analyses will be performed on the Cancer Registry’s secure server, and all project members are subject to a duty of confidentiality. The Regional Committee for Medical and Health Research Ethics (REK) give ethical assessment and legal approval for the execution of the project.

Status (as of 12^th Jan, 2024)

First interim report delivered, and one manuscript submitted to a scientific journal.

Dissemiation

Results from the project will be published in open access journals.

Orumaa M, Lahlum EJ, Gulla M, Tota J, Nygård M, Nygård S. Quadrivalent HPV vaccine effectiveness against cervical intraepithelial lesion grade 2 or worse in Norway: A registry-based study of 0,9 million Norwegian women. J Infect Dis. 2024 Apr 25:jiae209. doi: 10.1093/infdis/jiae209. Epub ahead of print. PMID: 38658353.

Participant information

Right to Reservation and Information Security:

The study utilizes health information from the Cancer registry, the Norwegian prescribed drug registry (legemiddelregisteret), and the Norwegian Immunization Registry (SYSVAK).

The availability of this information has been approved under the authority of the Health Registry Act, sections 19b and 19c.

A data protection impact assessment (DPIA) has been conducted and approved by the Data Protection Officer at Oslo University Hospital (OUS).

Your rights to access your information:

You have the right to access the information that is stored about you. If you wish to access your information, this request should be directed directly to the relevant registry. Information on how to request access to the various registries can be found by following the links below:

The Cancer Registry of Norway - Presciption database - National vaccination Registry