Gardasil is a vaccine that targets four strains of human papillomavirus (HPV). Those strains are called HPV-6, HPV-11, HPV-16, and HPV-18.
HPV-16 and HPV-18 account for about 70% of all cervical cancers. Cervical cancer is cancer of the cervix, which connects the vagina to the uterus.
HPV-6 and HPV-11 account for about 90% of genital warts.
The vaccine is also approved to help prevent vaginal and vulvar cancers, which can also be caused by HPV.
2. How does HPV spread?
HPV is spread through sex. HPV infection is common. About 20 million people in the U.S. are infected with HPV, and by age 50, at least 80% of women will have had an HPV infection, according to the CDC.
Most women with HPV infection don't develop cervical cancer.
3. Does Gardasil protect against all cervical cancers?
No. Though the vaccine protects against leading causes of cervical cancer, it doesn't ward off other causes of cervical cancer.
4. How effective is Gardasil?
Studies have shown 100% effectiveness in protecting against infection with HPV-16 and HPV-18 strains in people who had not been previously exposed to the virus.
5. How long does Gardasil last?
Tests show that the vaccine lasts at least four years. Long-term results aren't known yet.
6. Does the vaccine contain a live virus?
No. Gardasil contains a virus-like particle, but not the virus itself.
7. Who should get the vaccine?
The FDA approved Gardasil for girls and women aged 9-26. The FDA's decision doesn't automatically make the vaccine part of the CDC's recommended vaccine schedule.
The drug company Merck, which makes Gardasil, reportedly is studying the vaccine in women up to age 45 and may seek to broaden the approval group based on those results.
Merck is also continuing to research use of the vaccine in boys and men, as they can also become infected with HPV, which could lead to genital warts.