Longer term efficacy of a prophylactic monovalent human papillomavirus type 16 vaccine

Vaccine. 2009 Sep 18;27(41):5612-9. doi: 10.1016/j.vaccine.2009.07.027. Epub 2009 Jul 30.


We conducted an extended follow-up study (March 2006-May 2008) to assess the longer term efficacy of a prophylactic monovalent human papillomavirus (HPV) type 16 L1 virus-like particle vaccine in women (n=290) who had enrolled in a randomized controlled trial of this vaccine (October 1998-November 1999) in Seattle and remained HPV-16 DNA negative during the course of that trial. During the extended follow-up period, in the per-protocol susceptible population, none of the vaccine recipients was found to be infected with HPV-16 or developed HPV-16-related cervical lesions; among placebo recipients, 6 women were found to be infected with HPV-16 (vaccine efficacy [VE]=100%; 95% confidence interval [CI]: 29-100%) and 3 women developed HPV-16-related cervical lesions (VE=100%; 95% CI: <0-100%). Approximately 86% of vaccine recipients remained HPV-16 competitive Luminex immunoassay seropositive at an average of 8.5 years of follow-up. During the combined original trial and extended follow-up period, in the intention-to-treat population, 20 and 22 women developed any cervical lesion regardless of HPV type among the vaccine and placebo recipients, respectively (VE=15%; 95% CI: <0-56%). The results suggest that this monovalent HPV-16 vaccine remains efficacious through 8.5 years after its administration.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Capsid Proteins / immunology*
  • Cervix Uteri / pathology
  • Cervix Uteri / virology
  • Female
  • Follow-Up Studies
  • Human papillomavirus 16 / immunology*
  • Humans
  • Oncogene Proteins, Viral / immunology*
  • Papillomavirus Infections / prevention & control*
  • Papillomavirus Vaccines / immunology*
  • Placebos / administration & dosage
  • Time Factors
  • Uterine Cervical Neoplasms / prevention & control*
  • Vaccines, Virosome / immunology
  • Young Adult


  • Capsid Proteins
  • Oncogene Proteins, Viral
  • Papillomavirus Vaccines
  • Placebos
  • Vaccines, Virosome
  • L1 protein, Human papillomavirus type 16