Two Docs Say HPV Shot Might Not be so Hot

By Anastacia Mott Austin

The New England Journal of Medicine yesterday published an editorial by two UCSF doctors, George Sawaya and Karen Smith-McCune, entitled "HPV Vaccination – More Answers, More Questions."

The article addresses the new HPV (human papillomavirus) vaccine. Made by the drug company Merck, and marketed under the name Gardasil®, it is being widely touted as an anti-cervical cancer vaccine. Many studies show a connection between the common sexually transmitted disease HPV and cervical cancer.

The editorial in the New England Journal explains that in test trials, vaccinated women only received a .08% increased protection rate over non-vaccinated women for certain types of precancerous lesions, making the vaccine’s efficacy "modest" at best.

And while the doctors do feel that the vaccine does have some promise, showing effective prevention of some strains of HPV, they also write, "On the other hand, a cautious approach may be warranted in light of important unanswered questions about overall vaccine effectiveness, duration of protection, and adverse effects that may emerge over time" (New England Journal of Medicine, May 10, 2007, v. 356: pp1991-1993).

In the same issue of the NEJM, there are two reports of ongoing trials of the HPV vaccine. One of them reveals a concern that if the vaccine is effective against the two strains it purports to be, then one or more of the several other types of HPV viruses that can cause cervical cancer may proliferate, potentially causing more cases.

Nearly half of the state legislatures in this country are currently considering mandatory vaccination of middle-school aged girls with the Gardasil® vaccine. In February of this year, Texas Governor Rick Perry bypassed that state’s legislative process and issued an executive order mandating the shot series for girls entering middle school in Texas. That mandate has since been blocked, and Merck itself has backed off of its heavy lobbying of state officials to mandate the vaccine.

Gardasil® is considered a controversial vaccine by some, due to its fast-track onto the vaccination schedule by the FDA, the expense (at $360 per three-shot series, it is one of the most expensive vaccines ever made), and the lack of long-term testing.

W. Martin Kast, an immunologist at the Keck School of Medicine at the University of California, told reporters, "In a three-year follow up, it is very hard to reach statistical significance in a disease that takes about a decade to fully develop," agreeing that more time is needed to find out whether the vaccine can live up to its hype.

Dr. Smith-McCune, one of the authors of the NEJM editorial, told The San Francisco Chronicle, "At this stage, vaccination can still be considered experimental. To be discussing mandatory vaccination when the main clinical trials are still ongoing seems extremely premature."