Human papillomavirus (HPV) is usually passed from one person to another during direct skin-to-skin contact. HPV is the most common sexually transmitted infection in the United States. There are more than 150 different types of HPV. Most men and women have no symptoms or health problems to indicate when they have HPV.
Sometimes, certain types of HPV can cause warts on various parts of the body. Other types of HPV can cause cancer or precancerous lesions, which are abnormal growths that can turn into cancer.
Types of HPV and how HPV spreads
Most types of HPV can cause “common” warts. These warts grow on places such as the hands and feet. But more than 40 of the viruses are called “genital type” HPV. These viruses are spread from person to person when their genitals come into contact. This commonly occurs during vaginal, anal, and oral sex.
Genital HPV can infect a woman’s genital area, including inside and outside the vagina. They can also affect a man’s genital area, including the penis. In men and women, genital HPV can infect the anus or some areas of the head and neck. Sometimes genital HPV can cause warts or lesions. These growths vary in size, shape, and number, but they rarely lead to cancer. These are called low-risk HPV and include the strains HPV-6 or HPV-11.
High-risk HPV is more likely to cause cancer. For most people, the immune system is able to get rid of this type of infection. But some people develop a lasting infection. Over many years, the infection transforms normal cells into precancerous lesions or cancer. The following cancers are linked with HPV:
Cervical cancer. HPV infection causes nearly all cervical cancers. Of the cervical cancers related to HPV, about 70% are caused by 2 types: HPV-16 or HPV-18. Smoking may increase the risk of cervical cancer for women who have HPV. Although almost all cervical cancers are caused by HPV, it is important to remember that most genital HPV infections will not cause cancer.
Oral cancer. HPV can cause cancer of the mouth and tongue. It can also cause cancer of the oropharynx. This is the middle part of the throat, from the tonsils to the tip of the voice box. These HPV-related cancers are increasing in men and women. Changes in sexual behavior, including an increase in oral sex, may be contributing to the increase.
Other cancers. HPV is associated with less common cancers, including anal cancer, vulvar and vaginal cancers in women, and penile cancer in men.
Managing health problems from HPV
There is no cure for HPV, but doctors can often treat the warts and precancerous lesions caused by the infection through:
A loop electrosurgical excision procedure, which uses electric current to remove abnormal tissue
Medicated creams applied directly to the skin for genital warts
Removing genital warts does not mean a person no longer has HPV. Warts may return because the virus may remain in other cells in the body. A person with HPV who does not have any visible warts is still able to infect a sexual partner with the virus.
An inactive infection may become active when a person's immune system is weakened because of illness or drugs that suppress the immune system. Using a condom during sexual activity can lower the chance of infecting your partner.
Receiving an HPV vaccine reduces your risk of infection. These preventive vaccines cannot cure an existing HPV infection.
Purpose of the vaccine
The goal of vaccination is to prevent a lasting HPV infection after a person is exposed to the virus. Gardasil 9 helps prevent infection from HPV-16 and HPV-18 and 5 other types of HPV linked with cancer. The vaccine also protects people from the 2 low-risk types of HPV known to cause 90% of genital warts.
Gardasil 9 is approved for the prevention of cervical, vaginal, and vulvar cancers in girls and women ages 9 to 26. It is also approved to prevent anal cancer in women and men and genital warts in men and boys in the same age range. Two other vaccines have been discontinued for sale in the United States: Cervarix and the original Gardasil. These vaccines may be in use outside of the United States.
Effectiveness and safety of the vaccines
Studies show that HPV vaccinations are safe and highly effective in preventing a lasting infection. HPV vaccination has been shown to reduce precancerous lesions. Recent research also suggests that reducing precancerous lesions likely results in fewer cancers.
It is not known how long a single series of HPV vaccinations will last, if revaccination is required, and, if so, how often. Studies following people who have been vaccinated have been going on for up to 13 years. So far, the level of protection after exposure to the virus has not decreased. Continuing to follow-up with people who received a vaccine in clinical trials will provide important information about whether they will need the vaccine again.
Because a vaccine can only prevent infection, not cure an existing one, it is ideally given to people before they become sexually active. People who are already sexually active and who may already be infected with HPV should talk with their health care team about the vaccination. The vaccine may protect them from types of HPV that they do not have.
Other prevention strategies
An HPV test is a way to prevent cervical cancer in women 30 and older. During this test, a member of the health care team takes a sample of cells from the woman’s cervix. This sample is tested for the types of HPV most commonly linked to cervical cancer. HPV testing may be done by itself or combined with a Pap test. This test involves gathering a sample of cells from the cervix to look for abnormal changes in the cells. Often, the same sample can be used for both tests. HPV testing may also be done on a sample of cells from a woman’s vagina that she can collect herself.
A woman should talk with her health care team about HPV testing. There is no recommended HPV test for men.
Limiting your number of sex partners is another way to reduce your risk. Having many partners increases the risk of HPV infection. Using a condom cannot fully protect you from HPV during sex.
Questions to ask your health care team
Learn more about HPV by asking your health care team these questions:
What is my risk of getting HPV?
How can I reduce my risk of getting HPV?
Can I get genital HPV without having sex?
What are some of the signs and symptoms of HPV?
Should I be tested for HPV?
If the test shows that I have HPV, what happens next?
Should I receive an HPV vaccine? Why or why not?
Are HPV vaccines safe? What are the potential side effects?
How is an HPV vaccine given? Is more than 1 shot needed?
How long does an HPV vaccine last?
Does my health insurance cover the cost of an HPV vaccine?
I am pregnant and have HPV. Can it harm my baby?