Human Papillomavirus (HPV)

Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI) in the U.S. About 80 million people in the U.S. have HPV infection and nearly half of infections occur in teens and young adults aged 15 to 24. HPV infection can cause genital warts and can eventually lead to cancer.

Anyone who is sexually active can get HPV. Most sexually active people who are not vaccinated get HPV infection at some point in their lives, even if they only have one sexual partner.

HPV is spread through vaginal, anal and oral sex and can also be spread through genital-to-genital contact.

You can spread HPV even if you do not have symptoms.


Most people with HPV infection do not show symptoms. Some people with the infection may develop genital warts.

Cancer that results from HPV infections can take years to develop, and you may not experience symptoms until the cancer is advanced. Some HPV-associated pre-cancers can be detected through routine cervical and anal Pap tests. If left untreated, these pre-cancers can advance to cancer.

Cancers of the head, neck and throat (oropharynx) are the most common HPV-associated cancers in the U.S.

Cervical cancer is the most common HPV-associated cancer among women. Other HPV-associated cancers in women include:
  • Anal
  • Oropharyngeal (back of the throat, including the base of the tongue and tonsils)
  • Vulvar
  • Vaginal

HPV-associated cancers in men include:

  • Oropharyngeal
  • Anal
  • Penile


There is no treatment for HPV. Nine out of every 10 infections will clear on their own within two years. It is not possible to know which infections will persist and go on to cause further health problems, such as genital warts or cancer.

Genital warts can be removed with prescribed medications. Some warts also disappear on their own.

HPV-related cancers are most treatable when they are diagnosed and treated early. Starting at age 21, women should have routine cervical Pap testing. Certain people at higher risk for anal cancer, including men who have sex with men, may need routine anal Pap tests. Talk with your primary care provider about your risk and whether you should get tested.


The best way to prevent HPV is with a vaccine. Condoms and dental dams can lower the chance of spreading HPV, but HPV can still infect areas not covered by the condom or dental dam.

The HPV vaccine protects against nine types of the HPV virus, including the types that cause most cervical cancers. The vaccine is up to 99% effective in preventing cervical, vaginal and vulvar abnormalities, which can develop into cancer if left untreated. The vaccine also protects against most genital warts and anal cancers. Females who receive the vaccine are less likely to have abnormal Pap tests, cervical pre-cancer and genital warts.

The vaccine works best on people who have not been exposed to HPV. If you are sexually active and may have been exposed to HPV, the vaccine can still be effective. The vaccine protects against several types of HPV, and you likely may not have been exposed to one of those types of the virus.

Vaccine Recommendations

HPV vaccine is recommended for:

  • Children aged 11 or 12 (can be started at age 9)
  • Adolescents and young adults who did not finish the HPV vaccine series when they were younger should get it immediately.
  • Women up to age 26
  • Men up to age 21
  • Men aged 22 to 26 who have a higher risk of HPV infection, such as:
    • Men living with immunocompromising conditions, such as HIV
    • Men who have sex with men
    • Transgender men

Adolescents who start the series younger than 15 should receive two shots at least six months apart. Anyone who starts the series at 15 or older will require three shots given over six months.

Vaccine Side Effects and Safety

The HPV vaccine is safe and does not interfere with other vaccines. The HPV vaccine does not cause serious health problems. Serious side effects, such as severe allergic reactions, are rare.

Side effects are usually mild and short-lived. They include:

  • Soreness at the injection site
  • Fever
  • Headache
  • Nausea

Tell your doctor if you have any severe allergies, including to yeast. Anyone who has ever had a serious allergic reaction to any ingredient of the HPV vaccine , or to a previous dose of the HPV vaccine, should not get the vaccine.

People with a mild illness, such as a low-grade fever, cold, ear infection or mild diarrhea, can be vaccinated.

Vaccine in Pregnancy

The vaccine is not recommended for pregnant women and should not be given during pregnancy. However, studies do not show safety concerns for pregnant women or their unborn children if vaccine is given.

If a woman is found to be pregnant after starting the vaccination series, she should wait to finish the series until she is no longer pregnant.

Women who are breastfeeding may get the vaccine.

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