FDA, CDC back Merck's Gardasil shot as safe

WASHINGTON (Reuters) - Merck & Co's Gardasil vaccine remains safe and effective for protecting women and girls from a virus that causes cervical cancer, U.S. officials said on Tuesday after reviewing thousands of reports of health problems.

Consumers, doctors and others have raised questions about Gardasil's safety but the Food and Drug Administration and the Centers for Disease Control and Prevention said the most serious adverse events did not appear linked to the vaccine.

"Based on the review of available information by FDA and CDC, Gardasil continues to be safe and effective, and its benefits continue to outweigh its risks," a statement said.

The agencies said they reviewed more than 9,700 reports of health problems following Gardasil injections.

Six percent of the cases were deemed serious events. They included 20 deaths reported as of June 30.

"There was not a common pattern to the deaths that would suggest they were caused by the vaccine," the FDA and CDC statement said.

In cases where autopsy or other records were available, "the cause of death was explained by factors other than the vaccine," the agencies said.

Other serious problems that were reported included a rare neurological disorder called Guillain-Barre Syndrome. Data "do not currently suggest an association" between Gardasil and the condition, the FDA and CDC said.

Gardasil targets four strains of the human papillomavirus (HPV), a common sexually transmitted virus that causes genital warts and most cases of cervical cancer. It is approved for women and girls ages 9 to 26.