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TRENTON, N.J. -- An experimental vaccine to prevent the most common forms of cervical cancer proved 100 percent effective in a two-year test on more than 10,000 girls and women, drug maker Merck & Co. says.\nMerck is hoping to win Food and Drug Administration approval for the vaccine, Gardasil, and put it on the market as soon as late 2006. It would be the first vaccine to prevent cervical cancer, a disease caused almost exclusively by a highly common sexually transmitted virus called the human papilloma virus, or HPV.\nDoctors expect the vaccine to be routinely offered to girls -- and boys, too, because they can spread the virus to their partners -- before they become sexually active, though the practice is certain to run into opposition from conservatives and religious groups.\nWorldwide, cervical cancer is one of the most common cancers among women. It kills nearly 300,000 a year, including about 3,700 in the United States. About 20 million Americans have some form of HPV, which in addition to cervical cancer can cause painful genital warts.\nThe genetically engineered vaccine prevents cervical cancer by blocking infection from the two strains of HPV that cause 70 percent of all cases of the disease.\nThe study, which was funded by Merck, was presented Friday at a meeting of the Infectious Diseases Society of America.\n

Moon discovered orbiting so-called \n10th 'planet'

\nLOS ANGELES -- The astronomers who claim to have discovered the 10th planet in the solar system have another intriguing announcement: It has a moon.\nWhile observing the new, so-called planet from Hawaii last month, a team of astronomers led by Michael Brown of the California Institute of Technology spotted a faint object trailing next to it. Because it was moving, astronomers ruled it was a moon and not a background star, which is stationary.\nThe moon discovery is important because it can help scientists determine the new planet's mass. In July, Brown announced the discovery of an icy, rocky object larger than Pluto in the Kuiper Belt, a disc of icy bodies beyond Neptune. Brown labeled the object a planet and nicknamed it Xena after the lead character in the former TV series "Xena: Warrior Princess." The moon was nicknamed Gabrielle, after Xena's faithful traveling sidekick.\nBy determining the moon's distance and orbit around Xena, scientists can calculate the mass of Xena. \nBut the discovery of the moon is not likely to quell debate about what exactly makes a planet. The problem is there is no official definition for a planet and setting standards like size limits potentially invites other objects to take the "planet" label.