Human Papillomavirus (HPV) | The Children's Hospital of Philadelphia

Parents PACK

Human Papillomavirus (HPV)

General information

Please visit the Vaccine Education Center for general information about HPV and the vaccine.

Additional information from past issues of the Parents PACK newsletter

Adolescence and the HPV vaccine

Q. My daughter is not sexually active. Why should I even consider getting her vaccinated against the human papillomavirus (HPV) now?

A. The HPV vaccine is recommended before the start of sexual activity for two reasons:


Rates of HPV infection and cervical cancer

HPV is the most common sexually transmitted infection around the world. Each year, about 300,000 women die worldwide from cervical cancer.

In the U.S. each year, about 6 million people are infected with HPV, 10,000 women develop cervical cancer and 4,000 women die from cervical cancer. There are currently about 20 million Americans living with HPV.


The facts about human papillomavirus (HPV) and the vaccine

Surveys of adolescent girls suggest that many are not being immunized with the human papillomavirus (HPV) vaccine. Because some of the disinterest in the vaccine relates to misinformation about the disease and the vaccine, we felt it was important to provide accurate information.

Diseases and conditions caused by HPV

HPV is a family of viruses, some of which cause:

Transmission of HPV

HPV is transmitted by sexual contact, most often in the form of sexual intercourse. However, it can also be transmitted by genital-to-genital contact and oral sex.

Appearance of disease following infection

HPV infections are unique. First, most people never know they were infected. Unlike a cold in which symptoms develop a few days after exposure to the virus, HPV infections are typically not symptomatic. Second, HPV infections can last for long periods of time. The average length of infection is about eight months; however, for about 1 of every 10 women, the infection lasts longer than two years. It is in this group of women that there is an increased risk of developing cervical cancer. Cervical cancer often doesn’t occur until years after the initial infection.

Preventing HPV

The risk of contracting HPV can be reduced or prevented by:

Age recommendations

The HPV vaccine is recommended for girls between 11 and 12 years of age; however, those as young as 9 and women as old as 26 can also be immunized. Girls can get either version of the vaccine. Boys between the ages of 9 and 18 years of age can also get the HPV vaccine; however, only the Gardasil® vaccine, which contains four types of HPV, is licensed for use in boys.

Some parents do not want to give HPV vaccine to their adolescents because they are not yet sexually active and parents do not want to promote sexual activity; however, the vaccine will work best when given before any sexual activity, even if that activity occurs years later. Unfortunately, half of new infections each year are in teens and young adults between 15 and 24 years old. And studies have shown that HPV vaccine does not increase the likelihood of indiscriminate sexual activity.

Vaccine safety

HPV vaccines have been given to millions of people. Of those who got the vaccine, the most common adverse events were pain, redness or swelling at the injection site. Fainting has also been associated with the vaccine; therefore, patients should stay seated or lying down for about 15 minutes after getting the vaccine.

During a recent presidential primary debate, one candidate suggested that the vaccine can cause mental retardation; however, this condition has never been associated with the HPV vaccine nor does the timing make sense, since mental retardation is typically diagnosed in early childhood and the vaccine is given in adolescence.

Some parents have claimed that the vaccine caused blood clots, strokes or heart attacks. However, when these claims were investigated, no association was found. In most cases, use of birth control pills was linked to these outcomes.

Additional information


HPV testing: What you should know

Human papillomavirus (HPV) is the most common sexually-transmitted disease in the world. Even though a vaccine is available to prevent infection with some types of HPV, it’s important to realize that the vaccine does not prevent all types of HPV, so testing is still important.

HPV Biology

HPV is spread through genital contact, most often, but not always, during sex. There are about 100 different types of HPV, and infections occur in both men and women. HPV infections can cause genital warts or cancers of the cervix or other reproductive organs; however, the types that cause genital warts are not the same ones that cause cancer.

Most people with a HPV infection do not experience any symptoms, and their immune systems clear it without them ever knowing they were infected. However, others remain infected for an extended period of time, and it is in these people that cancers can develop, often about 20 to 25 years after the initial infection.

Getting tested


HPV tests for men are not available, and most HPV infections clear on their own without causing problems. However, health problems caused by HPV, which can include genital warts, anal cancer, penile cancer or cancers of the oropharynx, can be checked by visiting your doctor.

Learn more about HPV and men»


Women can get HPV tests and/or Pap tests to determine whether they have an HPV infection that can lead to cancer. Both tests detect early health problems that can lead to cervical cancer, but neither checks for warning signs of other cancers, fertility or other STDs. Although both tests have a common goal, they do have their differences:

Pap Test (Pap Smear)
HPV Test

If both tests are normal, it is highly unlikely that serious cervical cell changes will develop in the next three years; however, regular wellness visits should not be skipped.

If either test is abnormal, more testing will be completed. Abnormal results do not mean that you have cervical cancer, but that cells in your cervix could eventually become cancerous. However, finding the abnormal cells early allows for more successful treatment.


Updated: January 2013

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