"Although the number of serious adverse events is small and rare, they are real and cannot be overlooked or dismissed without disclosing the possibility to all other possible vaccine recipients," said Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at University of Missouri. "The rate of serious adverse events is greater than the incidence rate of cervical cancer."
As of June 1, 2009, the CDC reported that over 25 million doses of Gardasil, which is recommended for women between ages 9-26, have been distributed in the U.S. and there was an average of 53.9 VAERS reports per 100,000 vaccine doses. Of these, 40 percent occurred on the day of vaccination, and 6.2 percent were serious, including 32 reports of death.
In a statement yesterday from Merck, the pharmaceutical company that manufactures Gardasil, the company backed the vaccine's efficacy and said they encourage further research on its safety.
"We are pleased that the study published by JAMA [yesterday] further reinforces the safety profile of Gardasil," said Dr. Richard M. Haupt, head of the clinical program for Gardasil at Merck. "We welcome continued study and discussion about the safety of this important vaccine."
But some clinicians are not ready to accept wide use of the drug based on the available safety data.
Dr. Jacques Moritz, director of gynecology at St. Luke's-Roosevelt Hospital, said he would not offer the Gardasil vaccine to patients when good cervical cancer screening techniques and treatments exist. He has also chosen not to have his 11-year-old daughter get the HPV shot because of his concerns.
"I'm pro preventing cervical cancer and HPV," Moritz said. "I'm not pro that the physicians don't know the risks and side effects."
But clinicians on both sides of the vaccination debate agree that data provided by the VAERS report is limited because it lacks any baseline comparison for the adverse events reported. This makes it difficult to draw cause and effect relationships when a death, for example, occurs soon after administering the Gardasil vaccine.
In fact, the JAMA study authors showed that 90 percent of those with blood clots had typical risk factors for clots, outside of having received the vaccine -- using oral contraceptives, for example, or smoking.
"The problem is that there is a difference between an adverse reaction caused by the vaccine, as opposed to an adverse event reported in association with the vaccine," said Dr. Lauren Streicher, an obstetrician-gynecologist at Northwestern Medical School, who supports use of the vaccine. "Patients need to understand the true risk of the vaccine, as well as the risks of not getting the vaccine."
The overwhelming consensus regarding Gardasil use is that physicians who are not well versed in the risks of HPV and cervical cancer and the side effects of the vaccine cannot adequately counsel patients whether or not to be vaccinated.