Sustained efficacy up to 4.5 years of a bivalent L1 virus-like particle vaccine against human papillomavirus types 16 and 18: follow-up from a randomised control trial

Lancet. 2006 Apr 15;367(9518):1247-55. doi: 10.1016/S0140-6736(06)68439-0.

Abstract

Background: Effective vaccination against HPV 16 and HPV 18 to prevent cervical cancer will require a high level of sustained protection against infection and precancerous lesions. Our aim was to assess the long-term efficacy, immunogenicity, and safety of a bivalent HPV-16/18 L1 virus-like particle AS04 vaccine against incident and persistent infection with HPV 16 and HPV 18 and their associated cytological and histological outcomes.

Methods: We did a follow-up study of our multicentre, double-blind, randomised, placebo-controlled trial reported in 2004. We included women who originally received all three doses of bivalent HPV-16/18 virus-like particle AS04 vaccine (0.5 mL; n=393) or placebo (n=383). We assessed HPV DNA, using cervical samples, and did yearly cervical cytology assessments. We also studied the long-term immunogenicity and safety of the vaccine.

Findings: More than 98% seropositivity was maintained for HPV-16/18 antibodies during the extended follow-up phase. We noted significant vaccine efficacy against HPV-16 and HPV-18 endpoints: incident infection, 96.9% (95% CI 81.3-99.9); persistent infection: 6 month definition, 94.3 (63.2-99.9); 12 month definition, 100% (33.6-100). In a combined analysis of the initial efficacy and extended follow-up studies, vaccine efficacy of 100% (42.4-100) against cervical intraepithelial neoplasia (CIN) lesions associated with vaccine types. We noted broad protection against cytohistological outcomes beyond that anticipated for HPV 16/18 and protection against incident infection with HPV 45 and HPV 31. The vaccine has a good long-term safety profile.

Interpretation: Up to 4.5 years, the HPV-16/18 L1 virus-like particle AS04 vaccine is highly immunogenic and safe, and induces a high degree of protection against HPV-16/18 infection and associated cervical lesions. There is also evidence of cross protection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cervical Intraepithelial Neoplasia / etiology
  • Cervical Intraepithelial Neoplasia / prevention & control
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Multicenter Studies as Topic
  • Papillomaviridae / immunology*
  • Papillomavirus Infections / complications
  • Papillomavirus Infections / prevention & control*
  • Papillomavirus Vaccines*
  • Randomized Controlled Trials as Topic
  • Time Factors
  • Uterine Cervical Neoplasms / etiology
  • Uterine Cervical Neoplasms / prevention & control
  • Viral Vaccines / adverse effects
  • Viral Vaccines / classification
  • Viral Vaccines / immunology*

Substances

  • Papillomavirus Vaccines
  • Viral Vaccines