HPV infection and the HPV vaccine
How HPV is transmitted, who is at risk, what testing shows, the three vaccine types and their dose schedules, and why screening continues after vaccination.
What is HPV?
HPV — the human papillomavirus — is a sexually transmitted virus. It passes through genital contact, such as vaginal and anal sex, and also through skin-to-skin contact. In most people it produces no signs at all. HPV can clear on its own without causing any health problem.
Who can become infected?
Anyone who has genital contact with another person can carry HPV. Both men and women can acquire it and pass it on without knowing. Because there may be no signs, someone can have an HPV infection years after the sexual contact that caused it.
Who is at greater risk?
The likelihood of acquiring HPV is higher with first intercourse at an early age, with a large number of sexual partners, or with a partner who has had many partners.
If there are no symptoms, why worry about HPV?
There are more than 100 different types of HPV, and not all of them cause health problems. Some types can cause problems such as genital warts. Some can also cause cancer of the cervix, vagina, vulva or anus. Most of these problems are caused by types 6, 11, 16 and 18.
Is there a test for HPV?
Yes. It tests for the HPV types that can lead to cervical cancer. The FDA has approved HPV testing for use in women over 30. These tests can find HPV even before any change has occurred in the cervix. Women who have an HPV test still need to have a Pap smear.
Can HPV be prevented?
The FDA has approved vaccines that prevent certain diseases caused by some HPV types, including cervical cancer. Vaccination therefore provides protection against the types that carry a high cancer risk.
What else reduces the chance of acquiring HPV?
You may choose not to have sex (abstinence).
If you are sexually active, you can limit the number of partners you have.
How much protection condoms give against HPV is not known. Areas a condom does not cover can still be exposed to the virus.
Is there a treatment for HPV?
There is no treatment for the virus itself. There are treatments for the health problems HPV can cause: genital warts, changes in the cervix and cervical cancer.
What should I know about genital warts?
There are many treatment options for genital warts. But even after the warts have been treated, the virus may still be present and can pass to others. Left untreated, genital warts may clear, stay the same, or increase in size or number — but they do not turn into cancer.
What should I know about cervical cancer?
All women should have regular Pap smears. The Pap smear looks for the cell changes caused by HPV. It finds those changes early, so that the cells of the cervix can be treated before they turn into cancer. The test can also find cancer at an early stage, so that it can be treated before it becomes very serious. When the disease is caught early, death from cervical cancer is rare.
What should I know about vaginal and vulvar cancer?
Vaginal cancer is cancer of the vagina — the birth canal. Vulvar cancer is cancer of the clitoris, the labia and the opening of the vagina. Both of these are very rare. Not all vaginal or vulvar cancers are caused by HPV.
What is the HPV vaccine?
The primary aim of the HPV vaccine is to keep the virus in check. HPV is responsible for almost 99% of cervical cancers. Prophylactic vaccines developed against HPV provide primary prevention. The aim is to begin protection before HPV is acquired, and so to reduce the rate of cervical cancer, of other HPV-related cancers, and of the precursor lesions — tissue changes — that come before them. Three types of vaccine have been developed for this purpose: the quadrivalent vaccine (HPV types 6, 11, 16, 18), the nine-valent vaccine (6, 11, 16, 18, 31, 33, 45, 52 and 58) and the bivalent vaccine (16, 18).
Who can have the vaccine?
Ideally, the HPV vaccine is recommended for the 9-26 age group, before sexual activity has begun. It can, however, be given after the age of 26 as well. It can be given to both women and men. The vaccine is routinely recommended for girls and boys aged 11 or 12, but can be given from the age of 9. It is ideal for girls and boys to have it before sexual contact and before exposure to HPV.
Can the vaccine be given after sexual activity has begun?
Yes. Even if one HPV type has already been acquired through sexual contact, the vaccine can protect against the other types not yet present. None of the vaccines treats an existing HPV infection, though: they protect only against the types not already there.
The three vaccine types
- Bivalent: developed against HPV types 16 and 18. Effective against cervical cancer. Does not protect against genital warts.
- Quadrivalent: developed against HPV types 6, 11, 16 and 18. Effective against both cervical cancer and genital warts.
- Nine-valent: developed against HPV types 6, 11, 16, 18, 31, 33, 45, 52 and 58. Effective against the whole high-risk group that causes cervical cancer, and against genital warts.
In Türkiye, only the bivalent and quadrivalent vaccines are available.
Recommended ages and doses
For the bivalent and quadrivalent vaccines:
- Girls and boys under 14: two doses are sufficient. The second dose is given 6-12 months after the first.
- Girls and boys over 14: three doses are needed. The second dose comes 1 month after the first, and the third 6 months after the first.
Does the vaccine have side effects?
The HPV vaccine contains no live or killed organism, so it does not cause HPV infection, cancer or death. Like childhood vaccines, it can cause a mild fever and slight pain and redness at the injection site.
It does not cause problems in pregnancy. Even so, it is preferred not to give it to pregnant women. Someone who was vaccinated without knowing she was pregnant does not need to end the pregnancy.
Screening continues after vaccination. Genital warts occur in about 1% of the population; among people in their twenties the rate rises to 7%. Even after HPV vaccination, screening programmes must be continued. From the age of 21, all women are advised to have a Pap smear every three years.
Co-testing — HPV testing together with a Pap smear — is advised from the age of 30. If both come back clear, the chance of developing cervical cancer or a precancerous lesion within five years falls to 0.08%.
Does HPV affect men?
In men, HPV can cause warts and, if left untreated, can lead to cancer of the penis or anus. This is why men should be vaccinated against HPV too. HPV carried by men can also lead to cervical cancer in women.
This page is for information. It does not replace an examination or individual medical advice.