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Human Papillomavirus (HPV) FAQs

What is HPV?

According to the CDC, HPV is the most common sexually transmitted infection. HPV is a different virus than HIV and HSV (herpes). 79 million Americans, most in their late teens and early 20s, are infected with HPV. Some types of HPV can cause health problems including genital warts and cancers. But there are vaccines that can stop these health problems from happening. These vaccines are recommended for boys and girls as early as age 11.

Who should get HPV vaccine?

All girls and boys who are 11 or 12 years old should get the recommended series of HPV vaccine. The vaccination series can be started as early as age 9. Teen boys and girls who did not get vaccinated when they were younger should get it now. HPV vaccine is recommended for young women through age 26, and young men through age 21.

Why is HPV vaccine recommended at age 11 or 12 years?


For HPV vaccine to be most effective, the series should be given prior to exposure to HPV. There is no reason to wait to vaccinate until teens reach puberty or start having sex. Preteens should receive all recommended doses of the HPV vaccine series long before they begin any type of sexual activity.

How common are HPV infections?

HPV infections are so common that nearly all 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 sex partner without knowing it. Nearly 80 million Americans are currently infected with some type of HPV. About 14 million people in the United States become newly infected each year.

What kinds of problems does HPV infection cause?

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 last longer, 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 both women and men.

Every year in the United States, HPV causes 33,700 cancers in men and women.

How do people get an HPV infection?


People get HPV from another person during intimate sexual contact. Most of the time, people get HPV from having vaginal and/or anal sex. Men and women can also get HPV from having oral sex or other sex play. A person can get HPV even if their partner 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 possible for someone to get more than one type of HPV.

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

There haven’t been any documented 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.

Why are two doses recommended for 9–14 year olds, while older adolescents need three doses?

Since 2006, HPV vaccines have been recommended in a three-dose series given over six months. In 2016, CDC changed the recommendation to two doses for persons starting the series before their 15th birthday. The second dose of HPV vaccine should be given six to twelve months after the first dose. Adolescents who receive their two doses less than five months apart will require a third dose of HPV vaccine.

Teens and young adults who start the series at ages 15 through 26 years still need three doses of HPV vaccine Also, three doses are still recommended for people with certain immunocompromising conditions aged 9 through 26 years.

CDC makes recommendations based on the best available scientific evidence. Studies have shown that two doses of HPV vaccine given at least six months apart to adolescents at age 9–14 years worked as well or better than three doses given to older adolescents and young adults. Studies have not been done to show this for adolescents starting the series at age 15 years or older.

How well does HPV vaccine work?

HPV vaccines work extremely well. Clinical trials showed HPV vaccines provide close to 100% protection against cervical precancers and genital warts. Since the first HPV vaccine was recommended in 2006, there has been a 64% reduction in vaccine-type HPV infections among teen girls in the United States. Studies have shown that fewer teens are getting genital warts and cervical precancers are decreasing. In other countries, such as Australia, where HPV vaccination coverage is higher than in the United States, large decreases have been observed in these HPV-associated outcomes. HPV vaccines offer long-lasting protection against HPV infection and HPV disease. There has been no evidence to suggest that HPV vaccine loses any ability to provide protection over time. Data are available for about 10 years of follow-up after vaccination.

Like all vaccines, HPV vaccine is monitored on an ongoing basis to make sure it remains safe and effective. If it turns out that protection from HPV vaccine is not long-lasting, then the Advisory Committee on Immunization Practices would review the data and determine whether a booster dose would be recommended.

Even if it has been months or years since the last shot, the HPV vaccine series should be completed—but they do not need to restart the series.

HPV vaccine is recommended based on age, not sexual experience. Even if someone has already had sex, they should still get HPV vaccine. Even though a person’s first HPV infection usually happens during one of the first few sexual experiences, a person might not be exposed to all of the HPV types that are covered by HPV vaccines.

How do we know that the HPV vaccine is safe?


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 ten 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.

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