What Is Human Papillomavirus?

Human papillomaviruses (HPV) are a group of more than 100 viruses.

Certain types of HPV can cause genital warts, which are growths or bumps that appear:

  • On the vulva
  • In or around the vagina or anus
  • On the cervix
  • On the penis, scrotum, groin, or thigh

Some strains of HPV are linked to cervical cancer. Although it is less common, some strains are linked to cancers of the vulva, anus, throat, and penis.

HPV is easily spread during oral, genital, or anal sex with an infected partner.

Many people will be exposed to a form of HPV at some point in their lives. Not all will become infected or develop symptoms.

What Is the HPV Vaccine?

The HPV vaccine contains virus-like particles that are not infectious. These particles produce antibodies to prevent HPV from infecting cells. The vaccine is given by injection into the muscle.

The vaccine Gardasil protects against four types of HPV strains. It may be used to prevent the following conditions:

  • Cancers of the cervix, vagina, vulva, and anus
  • Genital warts
  • Precancerous lesions on the genitals (in women)

Another vaccine called Cervarix protects against two types of HPV strains. It is used to prevent cervical cancer and cervical precancer in women.

Who Should Be Vaccinated and When?

The vaccine is recommended for girls as a 3-dose series between 11 and 12 years old. Girls should be vaccinated before their first sexual contact for the vaccine to be most effective. Girls and women aged 13-26 years who did not receive the HPV vaccine when they were younger should still receive the vaccine series.

It is recommended that boys receive 3 doses of Gardasil beginning at age 11-12 years. Boys and men aged 13-21 years who did not receive the HPV vaccine when they were younger should still receive the vaccine series.

Men aged 22-26 years may also be vaccinated. Men in this age group should be vaccinated if they have sex with other men, have HIV infection, or have a weak immune system due to other illnesses or medications.

What Are the Risks Associated With the HPV Vaccine?

Research suggests that the vaccine does not appear to cause any serious side effects. Like any vaccine, it has the potential to cause serious problems, such as a severe allergic reaction.

Some problems have been associated with the HPV vaccines, like pain, redness, swelling, or itching at the injection site. Other potential side effects include:

  • Gardasil
    • Headache
    • Mild to moderate fever
    • Fainting
  • Cervarix
    • Fatigue
    • Headache
    • Muscle pain
    • Joint pain
    • Gastrointestinal symptoms
    • Fainting
Who Should Not Be Vaccinated?

Do not get the vaccine if you:

  • Had a life-threatening allergic reaction to yeast or any other component of the vaccine.
  • Are or may be pregnant.
  • Are moderately or severely ill. Wait until you have recovered.
What Other Ways Can HPV Be Prevented Besides Vaccination?

Avoiding physical contact with an infected sexual partner is the only way to completely prevent the spread of a genital HPV infection. Latex condoms may help reduce the spread. However, condoms are not 100% effective because they do not cover the entire genital area.

Other preventive measures include:

What Happens in the Event of an Outbreak?

According to the Centers for Disease Control and Prevention (CDC), about 6 million new cases of sexually transmitted HPV infections are reported each year. Twenty million people in the United States are already infected. HPV vaccines cannot treat infections that already exist. The best way to prevent further spread of the disease is to get the vaccine before becoming infected.