"I thought I was protecting my daughter."
Tammy Harper, 42, now fears that vaccinating her 14-year old daughter against several strains of the human papilloma virus, or HPV, may not have been the right thing to do.
Harper, from Merrit Island, Fla., is one of many parents gripped by doubt about the safety of Gardasil, the 3-dose vaccine that promises to protect against cancer-causing HPV infections, following media reports this week on government data that called the vaccine's safety into question.
Despite her initial reservations about Gardasil being a relatively new drug without data on long term side effects, Harper said her daughter's pediatrician strongly recommended the vaccine. In addition, she feared cancer, having seen a family friend succumb to ovarian cancer.
"I wanted to know ... is it going to keep the cancer [away]," Harper said. "I'm concerned now that I've given her a vaccine that's supposed to protect her. Now who knows what I've condemned her to?"
The government report released Tuesday linked Gardasil to 32 unconfirmed deaths as well as incidents of blood clots and neurological disorders. More common, non-life threatening side effects of the vaccine included fainting, nausea and headaches. All adverse effects occurred in a pool of over 25 million doses of Gardasil administered in the U.S.
To date, none of the official recommendations regarding Gardasil use, which is indicated for girls and women between ages 9-26, have changed.
"We recommend the completion of the series of three doses of HPV vaccine within the recommended window for optimal effectiveness," said Arleen Porcell-Pharr, a spokesperson for the Centers for Disease Control and Prevention. "We don't have enough data to analyze how effective the vaccine is with only two doses. In the event the person can't follow the recommended schedule, we still want the person to complete the series, no matter how long it takes."
Parents whose daughters have received one or two doses of Gardasil may fear that they have ventured down a one-way path where they have no choice but to await a bad reaction to the vaccine.
But experts are quick to point out that if a patient has not exhibited adverse reactions after receiving one or more vaccine injection, they are unlikely to do so. Stopping the course of treatment has no evident medical drawback beyond failure to protect against HPV.
"We continue to counsel anyone who has already started the vaccine to continue the vaccine, especially if they've had no adverse reactions," said Dr. Eugene Shapiro, associate chair of the Department of Pediatrics at Yale University School of Medicine.
In fact, Dr. Richard M. Haupt, head of the clinical program for Gardasil at Merck, the vaccine's manufacturer, said the small number of adverse events reported supported the vaccine's safety. As to whether or not to continue or discontinue the vaccination course, Haupt said that decision was for a family to make.
"Obviously that decision and discussion is important to occur between a family and their healthcare provider," he said. "But for maximal benefit, all three doses should be given."
Other doctors say that deciding to get or continue getting the Gardasil vaccine depends largely on a family's tolerance for risk.
"If they've only had one dose and they've had no problems with it, it could make sense to pull out and not do any more doses," said Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at University of Missouri. "If they've had two doses, they've already swallowed the fish hook. If nothing bad happened, after the third dose the chances of an [adverse event] are really, really small."
Harper added that parents, particularly those whose daughters are 11-12 years old, may want to carefully consider whether to continue administering Gardasil compared to girls who are receiving the vaccine in their late teens or early 20s, when the vaccine has a greater beneficial impact.
But others argue that vaccinating early provides protection before exposure to HPV and would not counsel the parents of a pre-teen differently than the parents of an older girl.
"At that [11-12] age group, they are getting lots of other shots, they're in the pediatrician's office," said Dr. Kevin Ault, associate professor of Gynecology and Obstetrics at Emory University. "If anything we want to aim younger rather than older."
The uncertainty of future consequences of the vaccine may be most troubling to parents who wish to protect their daughters from HPV and potential cervical cancer.
"I'm worried about the long-term effects of a vaccination [for which] they don't know the results," said Mimi Denhart, 45, whose 12-year-old daughter received her first dose of Gardasil last week.
Shapiro said that the long-term effects are not known and cannot be known until after future analysis but that any potential risk is a well calculated one.
"That effectiveness is going to be long term ... takes a certain leap of faith but it has been true of most vaccines," he said. "We can change and adapt as we get more information, but the best information [available] now is that the benefits exceed the risks."