What is human papillomavirus?

Human papillomavirus (HPV) is the main cause of cervical cancer. More than 10,000 women in the United States get cervical cancer each year, and most cases are associated with HPV.

The virus affects both men and women. It's the cause of anal, mouth, throat, penile, vaginal, and other cancers, as well as genital warts, which are found in about 6 in 100 sexually active adults in the United States.

HPV is the most common sexually transmitted infection (STI), and most infected people don't even realize they have it or that they're passing it to their sexual partners. There are several types of HPV, and you can become infected with more than one type. It's so commonplace that it's estimated that most sexually active men and women will get HPV in their lifetime.

"Sexually active" doesn't necessarily mean having sex with lots of people. It simply means that you've had sex with at least one person. And if that person had sex with at least one other person, you're at risk.

You can also have HPV even if you haven't had sex for many years or haven't had sexual contact with an infected person for many years. Of course the more people you or your partner have had sex with, the greater the risk.

About 79 million Americans are infected with the virus, and 14 million more become infected every year. For most, the virus clears from the body naturally within two years.

Unfortunately, there's no routine way to be tested for HPV. The only approved HPV tests available are used to screen women older than 30 for cervical cancer. And there's no approved HPV test for men.

Thanks to the vaccine, the HPV rate has dropped by more than half among teenage girls in the United States. However, only about third of all girls and even fewer boys get fully vaccinated.

HPV vaccines

There are two HPV vaccines licensed by the U.S. Food and Drug Administration (FDA) and recommended by the U.S. Centers for Disease Control (CDC): Gardasil and Cervarix.

How the vaccines are similar:

  • Both vaccines are very effective against HPV types 16 and 18, which are associated with most cervical and anal cancers.
  • Both vaccines are very safe.
  • Both vaccines are made with very small parts of the virus and can't cause an HPV infection.
  • Both are injected and require three doses.

How the vaccines are different

  • Gardasil also protects against HPV types 6 and 11. These HPV types cause most genital warts in females and males.
  • Gardasil has also been shown to protect against anal, vaginal, and vulvar cancers.
  • The vaccines have different adjuvants (the substance that's added to the vaccine to improve the body's immune response).

Who can get the HPV vaccines, and when?

In 2012, the American Academy of Pediatrics (AAP) and the CDC began recommending the HPV vaccine as a routine vaccination for both girls and boys.

Girls can get Gardasil (for protection against cervical, anal, vaginal, and vulvar cancers as well as genital warts) or Cervarix (for protection against cervical cancer). The CDC recommends that girls get the same brand of vaccine for all three doses.

Boys can get Gardasil for protection against genital warts and anal cancer.

Recommended doses and ages

For girls and women: three doses of either Gardasil or Cervarix at age 11 or 12 (or at age 13 to 26 for those didn't get any or all of the shots previously)

For boys and men: three doses of Gardasil at age 11 or 12 (or at age 13 to 21 for those who didn't get any or all of the shots previously)

Females have a higher risk of HPV than males, which is why the CDC recommends a wider age range for girls and women. Men can also be vaccinated through age 26, but the CDC recommends completing vaccination by age 21.

Recommended dosing schedule

For both sexes: The second dose should be given one to two months after the first. The third dose should be given six months after the first.

Why is the vaccine recommended at age 11 or 12?

The vaccine is most effective when given during the preteen years. And vaccinating before your child is sexually active helps ensure protection through young adulthood.

For the HPV vaccine to work best, it's very important to get all three shots before being exposed to the virus. Someone can be infected with HPV the very first time they have sexual contact with another person.

Doctors recommend the first dose of an HPV vaccine be given to 11- and 12-year-olds at their routine preteen health checkup. HPV vaccines can safely be given at the same time as other preteen vaccines.

A checkup in the preteen years is also a time when adolescents and their parents can talk to their providers about other ways to stay sexually healthy and safe.

People who have had sexual contact before getting all three doses of an HPV vaccine might still benefit if they weren't infected before vaccination with the HPV types included in the vaccine they received.

Will someone who doesn't get all three doses be protected?

No studies so far have shown whether one or two doses protect as well as three doses, so it's very important to get all three.

Are HPV vaccines safe and effective?

The FDA has licensed the vaccines as safe and effective. Both vaccines were tested in thousands of people around the world.

These studies showed no serious side effects. The CDC says the vaccine can prevent about 21,000 HPV-related cancers each year.

What are the possible side effects?

Common, mild side effects included pain and redness or swelling at the injection site, fever, headache, and nausea. Fainting after being vaccinated has also been reported. As with all vaccines, the CDC and FDA continue to monitor the safety of these vaccines very carefully.


Can the HPV vaccines prevent other diseases?

Studies have shown that Gardasil prevents cancers of the vagina and vulva, which, like cervical cancer, can be caused by HPV types 16 and 18. Studies of Cervarix have not specifically looked at protection against vaginal and vulvar cancers. Gardasil also protects against anal cancer in males and females.

Published studies have not looked at other health problems that might be prevented by HPV vaccines. It's possible the HPV vaccines will also prevent cancers of the head and neck, and of the penis, caused by HPV 16 or 18. Gardasil might prevent recurrent respiratory papillomatosis (RRP), a rare condition caused by HPV 6 or 11 in which warts grow in the throat.

Why aren't HPV vaccines recommended for people older than 26?

Both vaccines were studied in thousands of people from 9 to 26 years old and found to be safe and effective. The FDA will consider licensing HPV vaccines for other ages if new studies show that this would also be safe and effective.

Is HPV vaccination covered by health insurance?

Most health insurance plans cover recommended vaccines. Some insurance plans don't cover any or all vaccines. Check with your provider to find out whether the cost of the vaccine is covered.

How can my child get an HPV vaccine if I don’t have insurance?

The Vaccines for Children (VFC) program helps families of uninsured or underinsured children who might not otherwise have access to vaccines. The program provides vaccines at no cost to doctors who serve eligible children. For more information, visit the CDC's website.

Learn more

You'll find more detailed information about the vaccine on the CDC's Human Papillomavirus page.

See our article on HPV during pregnancy.

To track your child's immunizations, use BabyCenter's Immunization Scheduler.