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Questions and Answers

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HPV vaccine protects against cancers caused by human papillomavirus (HPV) infection.  HPV vaccine is safe, effective, and can protect people from most of the cancers caused by HPV.

About HPV

Q: How many types of HPV are there?

A: More than 40 HPV types can infect the genital areas of males and females. These HPV types can also infect the mouth and throat. Most people who become infected with HPV do not know they have it.

Q: How common is HPV?

A: HPV is the most common sexually-transmitted infection in the US. HPV is so common that nearly all sexually active men and women will get at least one type of HPV at some point in their lives. Most people never know that they have been infected and may give HPV to a partner without knowing it. About 79 million Americans are currently infected with HPV. About 14 million people become newly infected each year.

Q: If HPV infection is so common, is it really that bad?

A: Most people with HPV never develop symptoms or health problems. Most HPV infections (9 out of 10) go away by themselves within two years. But, sometimes, HPV infections will persist and can cause certain cancers and other diseases. HPV infections can cause:

  • cancers of the cervix, vagina, and vulva in women;
  • cancers of the penis in men;
  • and cancers of the anus and back of the throat, including the base of the tongue and tonsils (oropharynx) in women and men.

HPV can also cause genital warts in men and women. The types of HPV that can cause genital warts are not the same as the types of HPV that can cause cancers.

Q: How many people get cancer and/or genital warts from HPV?

A: Every year, about 17,600 women and 9,300 men are affected by cancers caused by HPV. About 180,000 women and 160,000 men are affected by genital warts caused by HPV every year. Also, about 1 in 100 sexually active adults in the United States have genital warts at any given time.

Q: How do people get HPV?

A: People get HPV from another person during sexual activity. Most of the time people get HPV from having vaginal and/or anal sex. Men and women can also get HPV from having oral and other sex play. A person can get HPV even if their partner (straight or same-sex) doesn’t have any signs or symptoms of HPV infection. A person can have HPV even if years have passed since he or she had sexual contact with an infected person. Most people do not realize they are infected. They also don’t know that they may be passing HPV to their sex partner(s). It is also possible for someone to get more than one type of HPV.

Q: What other ways someone could get HPV?

A: It’s not very common, but sometimes a pregnant woman with HPV can pass it to her baby during delivery. In these cases, the child can develop recurrent respiratory papillomatosis (RRP), a rare condition where warts caused by HPV (similar to genital warts) grow in the throat.

Q: Can you get HPV from the toilet seat?

A: There haven’t been any cases of people getting HPV from surfaces in the environment, such as toilet seats. However, someone could be exposed to HPV from objects (toys) shared during sexual activity if the object has been used by an infected person.

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HPV Vaccine

Q: Who should get HPV vaccine?

A: All girls and boys who are 11 or 12 years old should get the recommended series of HPV vaccine. Teen boys and girls who did not get the vaccine when they were younger should get it now. Young women can get HPV vaccine through age 26, and young men can get vaccinated through age 21. The vaccine is also recommended for

  • gay and bisexual young men (or any young man who has sex with men) through age 26 and
  • young men with weakened immune systems (including HIV) through age 26, if they did not get HPV vaccine when they were younger.

Q: Why is the vaccine recommended at such a young age?

A: For HPV vaccines to be effective, they should be given prior to exposure to HPV. There is no reason to wait until a teen is having sex to offer HPV vaccination to them. Preteens should receive all three doses of the HPV vaccine series long before they begin any type of sexual activity and are exposed to HPV. Also HPV vaccine produces a higher immune response in preteens than it does in older teens and young women.

Q: Is the vaccine still effective if you have had sexual intercourse?

A: Even if someone has already had sex, they should still get HPV vaccine. Even though HPV infection usually happens soon after someone has sex for the first time, a person might not be exposed to any or all of the HPV types that are in the vaccine. Males and females in the age groups recommended for vaccination are likely to get at least some protection from the vaccine.

Q: Should boys get HPV vaccine too?

A: Two HPV vaccines—Gardasil® and Gardasil® 9—are also recommended for boys. These vaccines help prevent boys from getting infected with the types of HPV than can cause cancers of the back of the throat, penis, and anus. The vaccine also prevents genital warts. When boys are vaccinated, they are less likely to spread HPV to their current and future partners.

Q: How well does HPV vaccine work?

A: The HPV vaccine works extremely well. Clinical trials showed the vaccines provided close to 100% protection against precancers and, for Gardasil® and Gardasil®, 9 genital warts. Since the vaccine was first recommended in 2006, there has been a 56% reduction in vaccine type HPV infections among teen girls in the U.S., even with very low HPV vaccination rates. Research has also shown that fewer teens are getting genital warts. In other countries such as Australia where there is higher HPV vaccination coverage, HPV vaccine has also reduced the number of cases of precancers of the cervix in young women in that country. Also, genital warts have decreased dramatically in young women and men (85% and 71% respectively) in Australia since the HPV vaccine was introduced.

Q: How long will the HPV vaccine provide protection?

A: HPV vaccine offers long-lasting protection against HPV infection and HPV associated disease. Protection produced by HPV vaccine lasts at least 8-10 years according to data from clinical trials and ongoing research. There is no evidence to suggest that HPV vaccine loses the ability to provide protection over time.

Q: Will the vaccine require a booster?

A: In the U.S., the HPV vaccine series requires three shots given over six months; booster doses are not recommended. Like all vaccines, HPV vaccine is monitored continually to make sure it remains safe and effective. If protection from HPV vaccine doesn’t last as long as it should, then the Advisory Committee on Immunization Practices would review the data and determine if a booster shot should be recommended.

Q: Does someone have to restart the HPV vaccine series if too much time passes between the shots?

A: The Advisory Committee on Immunization Practices recommends that all three shots of the HPV vaccine series be given over six months; the second shot should be given one to two months after the first, and the third dose should be given six months after the first dose. However, if someone waits longer than that between shots, they do not need to restart the series. Even if has been months or years since the last shot, the series should still be completed.

Q: Does HPV vaccination offer similar protection from cervical cancer in all racial/ethnic groups?

A: Yes. Several different HPV types cause invasive cervical cancer. HPV vaccines are designed to target the HPV types that cause most invasive cervical cancers, so HPV vaccination will provide high protection for all racial/ethnic groups.

All HPV vaccines protect against types 16 and 18, which cause the majority of invasive cervical cancers across racial/ethnic groups (67% of the invasive cervical cancers among whites, 68% among blacks, and 64% among Hispanics).1 Along with protecting against types 16 and 18, the 9-valent HPV vaccine protects against five additional HPV types that cause invasive cervical cancer and two HPV types that cause genital warts. The 9-valent HPV vaccine is designed to protect against seven HPV types that cause about 80% of invasive cervical cancer among all racial/ethnic groups in the United States.

The most important thing is for all preteens to complete the HPV vaccine series before they turn 13. Teens and young adults who haven’t started or finished the HPV vaccine series should get make an appointment today to get vaccinated. For the best protection against cervical cancer, women should continue to get screened for cervical cancer and get follow-up care as recommended by their doctor or nurse.



  1. Saraiya M., Unger E. R., Thompson T. D., Lynch, C. F., Hernandez, B. Y., et al. US Assessment of HPV Types in Cancers: Implications for Current and 9-Valent HPV Vaccines. J Natl Cancer Inst (2015) 107 (6).
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HPV Vaccine Safety

Q: How do we know that the HPV vaccine is safe?

A: The United States currently has the safest, most effective vaccine supply in history. Years of testing are required by law to ensure the safety of vaccines before they are made available for use in the United States. This process can take 10 years or longer. Once a vaccine is in use, CDC and the Food and Drug Administration (FDA) monitor any associated side effects or possible side effects (adverse events) through the Vaccine Adverse Event Reporting System and other vaccine safety systems.

All three HPV vaccines—Cervarix®, Gardasil®, and Gardasil® 9—went through years of extensive safety testing before they were licensed by FDA. Cervarix was studied in clinical trials with more than 30,000 females. Gardasil trials included more than 29,000 females and males, and Gardasil 9 trials included more than 15,000 females and males. No serious safety concerns were identified in these clinical trials. FDA only licenses a vaccine if it is safe, effective, and the benefits outweigh the risks. CDC and FDA continue to monitor HPV vaccines to make sure they are safe and beneficial for the public.

Q: What are some possible side effects of HPV vaccination?

A: Vaccines, like any medicine, can have side effects. Many people who get HPV vaccine have no side effects at all. Some people report having very mild side effects, like a sore arm from the shot. The most common side effects are usually mild. Common side effects of HPV vaccine include:

  • Pain, redness, or swelling in the arm where the shot was given
  • Fever
  • Headache or feeling tired
  • Nausea
  • Muscle or joint pain

Brief fainting spells and related symptoms (such as jerking movements) can happen after any medical procedure, including vaccination. Sitting or lying down for about 15 minutes after a vaccination can help prevent fainting and injuries caused by falls.

On very rare occasions, severe (anaphylactic) allergic reactions may occur after vaccination. People with severe allergies to any component of a vaccine should not receive that vaccine.

Q: Will the vaccine cause cancer?

A: HPV vaccine cannot cause HPV infection or cancer. HPV vaccine is made from one protein from the virus that cannot cause HPV infection or cancer. Not receiving HPV vaccine at the recommended ages can leave one vulnerable to cancers caused by HPV.

Q: Will the vaccine cause fertility issues?

A: No. There are no data that suggest getting HPV vaccine will have an effect on future fertility. In fact, getting vaccinated and protecting against cervical cancer can help women have healthy pregnancies and have healthy babies.

Not getting the HPV vaccine leaves people vulnerable to HPV infection; for women, this could lead to cervical cancer. The treatment of cervical cancer (hysterectomy, chemotherapy, and/or radiation, for example) could leave a woman unable to have children. Even the treatment of cervical precancers caused by HPV can cause preterm labor or problems at the time of delivery.

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School Requirements and HPV Vaccine

Q: Why is this vaccine not mandatory for school entry?

A: Each state determines which vaccines will be required for school entry. Many factors are taken into consideration before requiring any vaccine for school entry, including: community support for the requirement, financial resources needed to implement the requirement, burden on school personnel for enforcing the requirement, vaccine supply, and current vaccination coverage levels.

HPV vaccine was first recommended for girls only, and many states did not want to implement a requirement that only applied to half the student population.

Healthcare providers do not need to wait to recommend and/or administer the HPV vaccine until there is a school requirement. Almost every state has a Tdap requirement for middle school entry. Providers should use this opportunity to administer HPV and quadrivalent meningococal conjugate vaccines.

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Paying for HPV Vaccine

Q: How can someone get help paying for HPV vaccine?

A: The Vaccines for Children (VFC) program helps families of eligible children who might not otherwise have access to vaccines. The program provides vaccines at no cost to children ages 18 years and younger who are uninsured, Medicaid-eligible, or American Indian/Alaska Native. To learn more, see VFC program.

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