Gardasil Side Effects Tough to Monitor

Incomplete reporting by manufacturer Merck calls the monitoring of adverse events into question.

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This week Gardasil, the vaccine that protects against the cervical-cancer-causing human papillomavirus, got a bit of a smack-down from two studies published in the Journal of the American Medical Association detailing safety risks associated with the vaccine and promotional tactics used by medical organizations to convince women and girls to get the vaccine. An editorial that accompanied the studies concluded that "the net benefit of the HPV vaccine is uncertain" since most women infected with HPV won't develop cervical cancer and thus should "be willing to accept only a small risk of harmful effects from the vaccine."

The study of safety risks, conducted by researchers at the Centers for Disease Control and Prevention, concluded that Gardasil still has a good safety profile. It did, however, find that the vaccine caused an increased risk of fainting and a slightly increased risk of blood clots, based on more than 12,000 adverse events reports filed with the government's Vaccine Adverse Event Reporting System database by patients, doctors, and Merck, the vaccine's manufacturer.

On its Web site today, the Food and Drug Administration reiterated its position that "Gardasil is a safe and effective vaccine" and noted that it will "continue to monitor" safety issues.

That's all very well and good, but the CDC study points out that the monitoring system has some significant flaws. The reporting of adverse events by doctors and patients is voluntary, so there is a considerable amount of underreporting. What's more, 68 percent of the reports were filed by Merck (which is required by law to hand over whatever information it receives on side effects via consumer phone calls or through clinical trials). Of the reports Merck filed, a whopping 89 percent didn't include "sufficient identifying information to allow medical review of the individual cases," the study's authors write.

How can that be? I asked Rick Haupt, Merck's head of the clinical program for Gardasil. "We provide the FDA and CDC with whatever data that we have," he tells me. "The reports that we're getting come from multiple sources: physicians, consumers, sometimes they're in the medical literature. Sometimes the reports are based on hearsay and are unverifiable." He says that could be the case with the four deaths reported by the manufacturer that the study authors wrote had "no identifying information for confirmation or medical review." One of my sources tells me that CDC officials would like consumers and physicians to file reports directly into the government's database instead of calling Merck.

The lack of information provided by Merck to the government has been particularly frustrating to parents who believe their daughters were harmed by Gardasil. Phil Tetlock, father of Jenny Tetlock, who died of a paralyzing condition about a year after receiving her third Gardasil shot, recently shared her autopsy report with me. The pathologist at the University of California-San Francisco who conducted the autopsy found that Jenny appears to have died from a neurological disease that was "mediated by immune responses," leading to extensive damage in her spinal cord. The pathologist noted that Jenny received the third dose of the HPV vaccine two months prior to the onset of her symptoms.

"All we know is that this is an atypical looking case," says Katherine Lomen-Hoerth, a UCSF neurologist who treated Jenny and reviewed the autopsy report. She is planning to compare tissue samples from Jenny's autopsy with those of Whitney Baird, a young woman who died of a paralyzing condition soon after receiving Gardasil, to see if they show similarities. "This certainly has raised a lot of questions," Lomen-Hoerth tells me. "But we need to do further work to see what it means."

Government officials agree. "I've seen the autopsy report, and it's another piece of information we need to consider," says Robert Ball, an FDA official and a coauthor of this week's JAMA study on safety risks. "But it's not really possible to draw any conclusions, to say that the vaccine had a definitive effect."

There's no question, though, that government scientists would have a far easier time studying these rare conditions that may or may not be related to Gardasil if they could see the full extent of the reporting. While Jenny's father and Whitney's mother made sure that complete VAERS reports on their daughters were put into the government's system, another young woman who died of similar paralyzing symptoms following Gardasil vaccination is impossible to identify. That report was filed by Merck.