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Why is the HPV vaccine important?

Updated: Nov 15, 2023

HPV vaccine
Why is HPV vaccine important

Genital HPV is a common virus that is passed from one person to another through direct skin-to-skin contact during sexual activity. Most sexually active people will get HPV at some time in their lives, though most will never even know it. HPV infection is most common in people in their late teens and early 20s. There are about 40 types of HPV that can infect the genital areas of men and women. Most HPV types cause no symptoms and go away on their own. But some types can cause cervical cancer in women and other less common cancers — like cancers of the anus, penis, vagina, vulva and oropharynx. Other types of HPV can cause warts in the genital areas of men and women, called genital warts. Genital warts are not life-threatening. But they can cause emotional stress and their treatment can be very uncomfortable.

What are HPV vaccines?

HPV vaccines protect against infection with human papillomaviruses (HPV). HPV is a group of more than 200 related viruses, of which more than 40 are spread through direct sexual contact. Among these, two HPV types cause genital warts, and about a dozen HPV types can cause certain types of cancer—cervical, anal, oropharyngeal, penile, vulvar, and vaginal.

Three vaccines that prevent infection with disease-causing HPV have been licensed in the United States: Gardasil, Gardasil 9, and Cervarix:

  • Gardasil: Gardasil targets four strains of human papillomavirus (HPV) -- HPV-6, 11, 16, and 18. Gardasil is a vaccine that is no longer available in the United States but is still used in other countries to prevent infection with the four types of human papillomavirus (HPV) that most often cause genital warts, certain precancerous lesions, and cancers of the cervix, vagina, vulva, and anus. Gardasil may also prevent HPV-related cancers of the penis and oropharynx. Also called recombinant human papillomavirus quadrivalent vaccine.

  • Gardasil 9: Gardasil 9 protects against nine HPV types (6, 11, 16, 18, 31, 33, 45, 52, and 58). Gardasil 9 is a vaccine that is FDA-approved for use in females and males aged 9 to 45 years to prevent infection with the nine types of human papillomavirus (HPV) that most often cause genital warts, certain precancerous lesions, and cancers of the cervix, vagina, vulva, anus, and head and neck, including the oropharynx. Gardasil 9 may also prevent HPV-related cancer of the penis. Also called recombinant human papillomavirus nonavalent vaccine.

  • Cervarix: Cervarix is designed to prevent infection from HPV types 16 and 18. A vaccine that is no longer available in the United States but is still used in other countries to prevent infection with the two types of human papillomavirus (HPV) that most often cause cervical cancer and lesions that may become cervical cancer. Cervarix may also prevent other HPV-related cancers. Also called recombinant human papillomavirus bivalent vaccine.

Gardasil 9 has, since 2016, been the only HPV vaccine used worldwide. It prevents infection with the following nine HPV types:

  • HPV types 6 and 11, which cause 90% of genital warts

  • HPV types 16 and 18, two high-risk HPVs that cause about 70% of cervical cancers and an even higher percentage of some of the other HPV-caused cancers

  • HPV types 31, 33, 45, 52, and 58, high-risk HPVs that account for an additional 10% to 20% of cervical cancers

These types of HPV also cause most anal cancers, and some genital and head and neck cancers. HPV types 6 and 11 cause around 90% of genital warts, so using Gardasil 9 helps protect girls and boys against both cancer and genital warts. HPV vaccination does not protect against other infections spread during sex, such as chlamydia, and it will not stop girls getting pregnant, so it's still very important to practice safe sex.

How Well Do These Vaccines Work?

HPV vaccination works extremely well. HPV vaccine has the potential to prevent more than 90% of HPV-attributable cancers.

  • Since HPV vaccination was first recommended in 2006, infections with HPV types that cause most HPV cancers and genital warts have dropped 88% among teen girls and 81% among young adult women.

  • Fewer teens and young adults are getting genital warts.

  • HPV vaccination has also reduced the number of cases of precancers of the cervix in young women.

  • The protection provided by HPV vaccines lasts a long time. People who received HPV vaccines were followed for at least about 12 years, and their protection against HPV has remained high with no evidence of decreasing over time.

Who Should Get an HPV Vaccine?

HPV vaccination is recommended at ages 11–12 years. HPV vaccines can be given starting at age 9 years. All preteens need HPV vaccination, so they are protected from HPV infections that can cause cancer later in life.

  • Teens and young adults through age 26 years who didn’t start or finish the HPV vaccine series also need HPV vaccination.

CDC recommends that 11- to 12-year-olds receive two doses of HPV vaccine 6 to 12 months apart.

  • The first dose is routinely recommended at ages 11–12 years old. The vaccination can be started at age 9 years.

  • Only two doses are needed if the first dose was given before 15th birthday.

Teens and young adults who start the series later, at ages 15 through 26 years, need three doses of HPV vaccine.

  • Children aged 9 through 14 years who have received two doses of HPV vaccine less than 5 months apart will need a third dose.

  • Three doses are also recommended for people aged 9 through 26 years who have weakened immune systems.

Vaccination is not recommended for everyone older than age 26 years.

  • Some adults age 27-45 years who are not already vaccinated may decide to get HPV vaccine after speaking with their doctor about their risk for new HPV infections and the possible benefits of vaccination for them.

  • HPV vaccination in this age range provides less benefit, because more people in this age range have already been exposed to HPV.

Who Should Not Get HPV Vaccine?

Tell your doctor about any severe allergies. Some people should not get some HPV vaccines if:

  • They have ever had a life-threatening allergic reaction to any ingredient of an HPV vaccine, or to a previous dose of HPV vaccine.

  • They have an allergy to yeast (Gardasil and Gardasil 9).

  • They are pregnant.

HPV vaccines are safe for children who are mildly ill, like those with a low-grade fever of less than 101 degrees Fahrenheit, a cold, runny nose, or cough. People with a moderate or severe illness should wait until they are better.

Why is the HPV vaccine given at such a young age?

HPV infections can be spread by any skin-to-skin contact and are usually found on the fingers, hands, mouth and genitals. This means the virus can be spread during any kind of sexual activity, including touching.

The HPV vaccine works best if girls and boys get it before they come into contact with HPV (in other words, before they become sexually active). So getting the vaccine when recommended will help protect them during their teenage years and beyond.

Most unvaccinated people will be infected with some type of HPV at some time in their life. The virus does not usually do any harm because the person's immune system clears the infection. But sometimes the infection stays in the body for many years, and then it may start to cause damage.

Does the HPV vaccine carry any health risks or side effects?

The HPV vaccine has been found to be safe in many studies.

Overall, the effects are usually mild. The most common side effects of HPV vaccines include soreness, swelling or redness at the injection site. Sometimes dizziness or fainting occurs after the injection. Remaining seated for 15 minutes after the injection can reduce the risk of fainting. Headaches, nausea, vomiting, fatigue or weakness also may occur. The CDC and the FDA continue to monitor the vaccines for unusual or severe problems.


This article is written by: dr. Natalia Liau, MBBS, Msc.



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