An experimental vaccine against the virus that causes most cancers of the cervix has passed—with flying colors—a test typically needed for regulatory approval.
The vaccine targets four strains of the sexually transmitted human papillomavirus (HPV), which infects about 20 million men and women in the United States. Last week in San Francisco at a meeting of the Infectious Diseases Society of America, researchers conducting a large trial in women reported that the vaccine prevented all cervical cancers and precancerous lesions traceable to the two most dangerous strains of the virus.
The vaccine, called Gardasil by its maker Merck & Co., targets four viral strains. Two of them, HPV-16 and HPV-18, account for most cervical cancers. The other two strains cause genital warts, which are difficult to treat but don't become cancerous.