New Gardasil vaccine protects against an additional 5 strains that cause cervical cancer

The drugmaker Merck & Co. Inc. has received approval for an updated version of its Gardasil vaccine that protects against an additional five strains of the virus that causes most cases of cervical cancer.

The Food and Drug Administration approved the company's Gardasil 9, which protects against nine strains of the virus called HPV, or human papillomavirus. That's up from four strains covered by its original vaccine approved in 2006.

The FDA says the updated Gardasil has the potential to prevent roughly 90 percent of cervical, vulvar, vaginal and anal cancers. It also guards against some types of genital warts. Original Gardasil protected against strains blamed for 70 percent of U.S. cervical cancers.

About 75 to 80 percent of men and women are infected with HPV during their lifetime. Most don't show symptoms.