Human papillomaviruses (HPV) are a group of more than 100 viruses. Certain types of HPV can cause genital warts, which are growths or bumps that appear:

  • On the vulva
  • In or around the vagina or anus
  • On the cervix
  • On the penis, scrotum, groin, or thigh

Some strains of HPV are associated with cervical cancer, or less commonly, cancers of the vulva, anus, or penis.

HPV is easily spread during oral, genital, or anal sex with an infected partner. About two-thirds of people who have sexual contact with a partner who has genital warts will develop them also. Usually this happens within three months of contact.

Most people will be exposed to a form of HPV at some point in their lives. Not all will become infected or develop symptoms. Warts can appear within several weeks after sexual contact with an infected person, or they can take months to appear.

The HPV vaccine consists of noninfectious virus-like particles. These particles produce antibodies to prevent HPV from infecting cells. The vaccine is given by injection into the muscle.

The vaccine Gardasil protects against four types of HPV strains. It may be used to prevent the following conditions:

  • In females:
    • Cancer of the cervix, vagina, vulvar, and anus
    • Precancerous lesions on the genitals
    • Genital warts
  • In males:
    • Anal cancer
    • Genital warts

Another vaccine called Cervarix protects against 2 types of HPV strains. It is used to prevent cervical cancer and cervical pre-cancer in women.