Human papillomavirus, vaccines and women's health: questions and cautions.(Research)(Clinical report)

[infinity] See related articles pages 456, 462, 464, 469 and 480

The federal government's recently announced $300 million investment toward a program for vaccinating girls and women with the currently available human papillomavirus (HPV) vaccine Gardasil, framed by some as a way to prevent cervical cancer in Canada, has generally been welcomed by a wide range of commentators. However, although HPV infection is necessary for the development of cervical cancer and the vaccine may prevent primary infection with HPV types 16 and 18 (currently thought to be the cause of about 70% of cervical cancer cases (1)), we propose that these facts be assessed within a broad context before immunization policies are implemented. A careful review of the literature, including that submitted by the manufacturer with its application for approval of Gardasil, reveals a sufficient number of unanswered questions to lead us to conclude that a universal immunization program aimed at girls and women in Canada is, at this time, premature and could possibly have unintended negative consequences for individuals and for society as a whole.

In this article we summarize some of the main questions and concerns that need to be addressed before there is a full-scale rollout of an HPV vaccination program (for supplementary material go to www.cwhn.ca/resources/cwhn/hpv-brief .html). These closely reflect issues raised in the analytical framework created by Erickson and colleagues2 in the context of the development of the National Immunization Strategy and support efforts to ensure a comprehensive and systematic evaluation of all relevant factors before decisions regarding the implementation of a new immunization program are made. As well, they echo some of the research questions identified as important in the final report from the Canadian Human Papillomavirus Vaccine Research Priorities Workshop, held in Quebec City in 2005.3 We hope raising these questions now will contribute to the deliberations necessary to ensure a responsible and transparent evidence-based decision-making process.

General questions and cautions

* There is no epidemic of cervical cancer in Canada to warrant the sense of urgency for a vaccination program initiated by the federal finance minister's announcement. According to 2006 Canadian cancer statistics, (4) cervical cancer is the 11th most frequent cancer affecting Canadian women and the 13th most common cause of cancer-related deaths, accounting for approximately 400 deaths per year. Both the incidence and mortality of cervical cancer have been declining in Canada, as in other resource-rich countries, although recently at a somewhat slower rate than has been observed in previous decades. (5) However, the incidence and mortality still…