HPV vaccine protects against cancers, genital warts

Arm with adhesive bandage placed by someone wearing blue gloves

HPV vaccine protects against cancers, genital warts

What parents need to know about human papillomavirus


Every year in the U.S., human papillomavirus (HPV) causes about 37,000 new cases of cancer. These are cancers that could have been prevented with the HPV vaccine.

Unfortunately, only 38.6% of children ages 9 to 17 had received at least one dose of the HPV vaccine in 2022, according to a recent report by the Centers for Disease Control and Prevention.  

We checked in with Dean Blumberg, chief of pediatric infectious diseases at UC Davis Children’s Hospital, to learn more. He answers some frequently asked questions about HPV, the HPV vaccine and what families need to know to protect their children from HPV-associated cancers through adulthood.  

What is HPV?

HPV is the most common sexually transmitted disease in the U.S. It is spread through genital contact and can cause cancers.

What are the signs and symptoms that someone has HPV?

People with HPV can be symptom-free, but they can still be infectious with no visible signs or symptoms. HPV causes a lot of different kinds of cancers in males and females — including cervical cancers and other cancers. These include cancer of the vulva, vagina, penis or anus. HPV can also cause cancer in the throat, tongue and the tonsils.

Genital warts can also result from different types of HPV. Genital warts usually appear as a small bump or group of bumps in the genital area. They can be small or large, raised or flat, or shaped like a small cauliflower. A health care provider can usually diagnose warts by looking at the genital area.

How can people avoid HPV?

Get vaccinated. The CDC recommends the HPV vaccination for all preteens (boys and girls) at age 11 or 12. Making sure preteens and teens receive their HPV vaccine now will protect them from these cancers when they are adults. It is a two-dose vaccine series for those ages 9-14. Older people can also get the vaccine — up to age 45. For those who start the vaccine at age 15 to 45, or for immunocompromised people, it’s a three-dose vaccine series.

To reduce the risk of HPV, those who are sexually active can also:

  • Use condoms to lower their chances of getting HPV, but HPV can infect areas of the body that condoms don’t cover. So condoms may not fully protect against getting HPV.
  • Have sex only with someone who only has sex with you (a mutually monogamous relationship).

How well does the HPV vaccine work?   

It’s been found to have close to 100% efficacy, one month after a person completes the full vaccination series. It prevents future HPV infection and prevents the spread of HPV as well. I let patients know that this is a powerful cancer prevention tool.

Who should not get the HPV vaccine?

  • Anyone who has had a life-threatening allergic reaction to any ingredient of an HPV vaccine or to a previous dose of HPV vaccine
  • Anyone with an allergy to yeast
  • Pregnant people

What are the side effects of the HPV vaccine?

The common side effects are pain, redness or swelling in the arm where the shot was given, fever, headache, muscle ache, nausea or dizziness. These side effects should improve within a day.

How long does the HPV vaccine protect people from HPV?

The vaccine provides a lifetime of protection. There is no need to get a booster for this.

But timing is important. The vaccine does not work to protect against HPV-associated cancers if someone already has HPV. It has to be administered before HPV exposure and infection. The vaccine is offered to preteens so the vaccine can provide that lasting protection into adulthood.

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