Lichtenfeld pointed out, as did the study authors, that because VAERS is a voluntary system, it might underestimate the actual number of adverse events because some could go unreported. "More specific scientific studies need to be done," he said.
As for the episodes of fainting, Merck -- as well as the CDC -- recommends that anyone receiving the vaccine stay in the doctor's office for at least 15 minutes after receiving a shot.
The CDC's Slade also recommended that parents drive their teens to their appointments so the teens are not driving if a fainting episode should occur. And, because vaccines are often administered during physicals for which people have been asked to fast, Slade also suggested eating a quick snack and drinking something before getting the vaccine but after having blood drawn for the physical.
The U.S. Centers for Disease Control and Prevention has more about the HPV vaccine.
SOURCES: Barbara Slade, M.D., M.S., medical officer, immunization safety office, U.S. Centers for Disease Control and Prevention, Atlanta; Richard Haupt, M.D., M.P.H., executive director, clinical research, infectious diseases and vaccines, Merck Research Laboratories, Whitehouse Station, N.J.; Len Lichtenfeld, M.D., deputy chief medical officer, American Cancer Society, Atlanta; Aug. 19, 2009, Journal of the American Medical Association
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