Vaccination against human papillomavirus

I read the commentary by Abby Lippman and colleagues on vaccination against HPV,1 and I was disturbed by the authors' statement about the scientific merit of the “handful of randomized controlled trials of sufficient quality to qualify for systematic review.” Unfortunately, the authors failed to elaborate on what they believe to be the limitations of these trials, the results of which were published in prestigious peer-reviewed journals such as Lancet, New England Journal of Medicine and Vaccine.1^–4

The trials, which involved 50 000 girls and women aged 9–26 years, were designed and conducted in 30 countries with the utmost scientific rigour. The results provide level 1 evidence of the immunogenicity, safety and efficacy of GlaxoSmithKline's Cervarix and Merck Frosst's Gardasil for at least 5 years after vaccination. The excellent quality of these randomized controlled trials led to the approval of Gardasil for use in girls and women aged 9–26 years in over 80 countries, including Canada.5 The only explanation I can envision for the authors' statement concerning the scientific merit of the trials is that they might have misinterpreted the methodology and statistical analyses detailed in the research papers published to date on the trials' results.

It is regrettable that Lippman and colleagues failed to recognize the scientific significance of the tremendous efforts and dedication of the hundreds of investigators around the world, including myself, who have been actively involved in Merck Frosst's and GlaxoSmithKline's randomized controlled trials. We, the investigators, consider the discovery and manufacture of prophylactic HPV vaccines to be the greatest milestone in cervical cancer prevention since the introduction of the Pap smear 50 years ago.