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"VAERS receives unconfirmed reports of possible side effects" that may require further study, Iskander tells WebMD. That is, the reports don't show whether Gardasil caused the reported problems. Publicity tends to increase VAERS reports, and Gardasil has gotten a lot of publicity, says Iskander.
The serious reported events are about half of what's average for vaccines overall, according to the CDC.
The CDC hasn't been able to establish Gardasil's role in 10 of the deaths reported to VAERS; patient information wasn't available for the other five reported deaths.
"Nonserious events" such as pain at the injection site and fainting made up 93% of the reported Gardasil adverse events in the VAERS database, says Iskander.
He notes that teens are particularly likely to faint after any vaccination, not just with Gardasil. The CDC recommends that health care providers observe patients for 15 minutes after vaccination with any vaccine. As for the pain reports, Gardasil "does seem to cause a bit more discomfort to some people, compared to some of the other vaccines given to teenagers," says Iskander.
Merck, which continues to monitor Gardasil's adverse events, stresses the fact that adverse event reports don't amount to proof of cause and effect.
Karen Smith-McCune, MD, PhD, associate professor of the department of obstetrics, gynecology, and reproductive science at the University of California, San Francisco, agrees that the VAERS data don't amount to proof.
But Smith-McCune, who has daughters in the age range for Gardasil vaccination, says she's waiting to see the final, published results from Gardasil's phase III clinical trials before she decides whether to let her daughters get vaccinated.
Merck presented those results to the CDC's Advisory Committee on Immunization Practices (ACIP) in February and plans to publish the findings later this year, Merck spokeswoman Amy Rose tells WebMD by email.
"That's great," says Smith-McCune. "Until we see the published, peer-reviewed final results from phase III trials, we don't have the gold standard of evidence for safety and efficacy."
Smith-McCune co-wrote an editorial in The New England Journal of Medicine in May 2008 recommending a cautious approach to the promising and apparently safe vaccine.