Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Sep 17:63:127632.
doi: 10.1016/j.vaccine.2025.127632. Epub 2025 Aug 23.

Impact of HPV vaccination on the incidence and clearance of HPV infections in sexually active young women

Pareesa Kassam  1 , Cassandra Laurie  1 , Mariam El-Zein  1 , Joseph E Tota  2 , Pierre-Paul Tellier  3 , François Coutlée  4 , Ann N Burchell  5 , Eduardo L Franco  6
Affiliations
Free article

Impact of HPV vaccination on the incidence and clearance of HPV infections in sexually active young women

Pareesa Kassam et al. Vaccine. .
Free article

Abstract

Background: Human papillomavirus (HPV) vaccination protects against new HPV infections, but seemingly no impact on the clearance of existing infections. We assessed the association between HPV vaccination and incidence and clearance of HPV infections among sexually active women in the Carrageenan-gel Against Transmission of Cervical HPV trial, conducted in Montreal, Canada (2013-2020).

Methods: Participants attended seven visits over 12 months, where they provided self-collected vaginal samples and completed questionnaires on risk factors. Participants self-reported their HPV vaccination status at screening, enrollment, and follow-up visits. Samples were genotyped for HPV using the Linear Array assay. We used Cox regression to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for incidence and clearance of HPV infections, with the unit of analysis being the HPV type. Analyses considered stringent (reported in ≥2 sources) and non-stringent (reported in ≥1 source) definitions of vaccination status. HPV types were classified as vaccine-targeted (HPVs 6/11/16/18) and non-vaccine-targeted (within-species: HPVs 31/33/35/39/44/45/52/58/59/67/68/70; cross-species: HPVs 26/34/40/42/51/53/54/56/61/62/66/69/71/72/73/81/82/83/84/89). To control for confounding, we applied inverse probability of treatment weights, based on study and participant characteristics.

Results: Of 461 participants, 45.8 % and 55.5 % were vaccinated according to the stringent and non-stringent definitions, respectively. Vaccination was associated with a lower risk of new HPVs 6/11/16/18 detection in the most stringent (HR = 0.41, CI:0.23-0.72) and least stringent (HR = 0.41, CI:0.23-0.72) definitions. Vaccination was not associated with incident within-species (most stringent: HR = 1.21, CI:0.90-1.64; least stringent: HR = 1.10, CI:0.82-1.48) or cross-species (most stringent: HR = 1.21, CI:0.94-1.55; least stringent: HR = 1.11, CI:0.87-1.41) HPV types. Vaccination did not impact clearance of baseline HPVs 6/11/16/18 (most stringent: HR = 1.23, CI:0.47-3.24; least stringent: HR = 1.40, CI:0.57-3.47), within-species (most stringent: HR = 1.50, CI:0.88-2.56; least stringent: HR = 1.58, CI:0.98-2.55) or cross-species HPV infections (most stringent: HR = 0.71, CI:0.49-1.03; least stringent: HR = 0.80, CI:0.56-1.16).

Conclusion: We found that HPV vaccination is effective as a prophylactic measure but has no therapeutic effects on existing infections.

Keywords: Clearance; HPV vaccination; Incidence; Self-reported vaccination; Vaginal HPV infections.

PubMed Disclaimer

Conflict of interest statement

Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Eduardo L Franco reports financial support was provided by Canadian Institutes of Health Research. Ann N Burchell reports financial support was provided by Canada Research Chair in Sexually Transmitted Infection Prevention (Tier 2). Ann N Burchell reports financial support was provided by University of Toronto Department of Family & Community Medicine. Eduardo L Franco reports financial support was provided by Investigator-Initiated Studies Program of Merck Canada Inc. Eduardo L Franco reports a relationship with Merck & Co Inc that includes: funding grants. Eduardo L Franco reports a relationship with Roche that includes: funding grants and non-financial support. Eduardo L Franco reports a relationship with GSK that includes: consulting or advisory. Francois Coutlee reports a relationship with Réseau FRQS-SIDA that includes: funding grants. Francois Coutlee reports a relationship with Merck & Co Inc that includes: funding grants. Francois Coutlee reports a relationship with Roche Diagnostics that includes: funding grants. Francois Coutlee reports a relationship with Becton Dickinson that includes: funding grants. Joseph E Tota reports a relationship with Merck Sharp & Dohme Corp that includes: employment. Eduardo L Franco has patent DNA methylation markers for early detection of cervical cancer pending to Office of Innovation and Partnerships, McGill University. Mariam El-Zein has patent DNA methylation markers for early detection of cervical cancer pending to Office of Innovation and Partnerships, McGill University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Substances

LinkOut - more resources