It may be a new form of protection against cervical cancer, but recent reports from the United States say a vaccination with Gardasil is painful and girls are fainting from the shot.(File Photo) Photo Gallery>>>

    BEIJING, Jan. 4 (Xinhuanet) -- It may be a new form of protection against cervical cancer, but recent reports from the United States say a vaccination with Gardasil is painful and girls are fainting from the shot.

    During its first year of use, reports of girls fainting from vaccinations climbed, but it's not clear whether the pain of the cervical cancer vaccine was the reason for the reaction. Gardasil is the first vaccine approved specifically to target the human papilloma virus, or HPV, which causes cervical and vaginal cancer. The Food and Drug Administration approved it for girls ages 9 to 26.

    "This vaccine stings a lot," said Patsy Stinchfield, an infectious disease expert at Children's Hospitals and Clinics of Minnesota, speaking at a recent meeting of vaccination experts in Atlanta.

    The pain is short-lived, girls say; many react with little more than a grimace. But some teens say it's uncomfortable driving with or sleeping on the injected arm for up to a day after getting the shot.

    Officials at Merck & Co., which makes the vaccine, acknowledge the sting. They attribute it partly to the virus-like particles in the shot. Pre-marketing studies showed more reports of pain from Gardasil than from dummy shots, and patients reported more pain when given shots with more of the particles.

    Meanwhile, U.S. health officials have noticed a rise in reports of vaccine-associated fainting in girls. From 2002-2004 there were about 50 reports of fainting; from 2005 until last July, there were about 230. About 180 of those cases followed a shot of Gardasil, which came on the market in 2006.

    But it's not clear that Gardasil's sting is related to the fainting increase, said Dr. Barbara Slade, an immunization safety specialist at the U.S. Centers for Disease Control and Prevention.

    Teens tend to faint from needles, so a three-dose vaccine for adolescents would be expected to prompt some added fainting, she said. Researchers aren't sure why teens faint more than other age groups, but nervousness may be a factor.