Questions & Answers

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When did HPV vaccine become available?
On June 8, 2006, the Food and Drug Administration (FDA) licensed the first vaccine developed to prevent cervical cancer and other diseases in females caused by certain types of genital human papillomavirus (HPV). The vaccine, Gardasil (by Merck), protects against four HPV types (6, 11, 16, 18) which are responsible for 70% of cervical cancers and 90% of genital warts. On October 16, 2009, a second HPV vaccine was licensed (Cervarix by GlaxoSmithKline) that protects against two types of HPV viruses – types 16 and 18.

What kind of vaccine is it?
HPV vaccine is an inactivated (not live) vaccine.

How is this vaccine given?
This vaccine is given as a shot in the muscle.

Who should get this vaccine?
In June 2006, the CDC's advisory committee (ACIP) voted to recommend routine vaccination of girls age 11-12 years, but the vaccine can be administered to girls as young as age 9 years. The vaccine was also recommended for females age 13-26 years who have not yet received or completed the vaccine series. In October of 2009, FDA licensed Merck's Gardasil vaccine for use in males ages 9 through 26 years for the prevention of genital warts caused by HPV types 6 and 11. ACIP subsequently provided guidance that Gardasil may be given to males aged 9 through 26 years to reduce their likelihood of acquiring genital warts.

The vaccine should be given as a series of three injections over a six-month period. The second dose should be given one to two months after the first dose and the third dose should be given six months after the first dose. The vaccine can be administered at the same visit as other needed vaccines.

It is best if the vaccine is given before onset of sexual activity. However, persons who are sexually active also may benefit from vaccination. Persons who have not been infected with any vaccine HPV type would receive the full benefit of vaccination and those who already have been infected with one or more HPV types would still get protection from the vaccine types they have not acquired. HPV vaccine can be given to females who have had an abnormal Pap test or genital warts. However, the vaccine will not have any helpful effect on existing Pap test abnormalities, HPV infection, or genital warts.

Why is the HPV vaccine licensed for girls and boys as young as 9 years of age?
This is because the vaccine is most effective in young people who have not yet acquired any of the HPV types covered by the vaccine so that they will receive the full benefits of the vaccine.

Why is the HPV vaccine not recommended for adults older than 26 years?
The vaccine has been widely tested in persons age 9 through 26 years. Research on the vaccine's safety and efficacy has only recently begun with older women. The FDA will consider licensing the vaccine for these women when there is research to show that it is safe and effective for them.

Should individuals be screened before getting vaccinated?
No. Girls/women do not need to get an HPV test or Pap test to find out if they should get the vaccine. An HPV test or a Pap test can tell that a woman may have HPV, but these tests cannot tell the specific HPV type(s) that a woman has. Even individuals with one HPV type could get protection from the other vaccine HPV types they have not yet acquired.

How effective is this vaccine?
Four studies, one in the United States and three multinational, were conducted to show how well Gardasil worked in women between ages 16-26 years. A total of 21,000 women were given either the vaccine or a placebo. The results showed that in women who had not already been infected, the vaccine was nearly 100% effective in preventing precancerous cervical lesions, precancerous vaginal and vulvar lesions, and genital warts caused by infection with the HPV types against which the vaccine is directed.

Two studies measured the immune response to the vaccine among younger females age 9-15 years. Their immune response was as good as that found in 16-26 year olds, indicating that the vaccine should have similar effectiveness when used in this younger age group In addition, over 4,000 males ages 16 through 26 years were involved in testing Gardasil for use in males. Efficacy for the prevention of genital warts among males who received all three doses of vaccine was nearly 90%.

A total of 18,644 females were studied as part of the licensure for the Cervarix vaccine. Efficacy against the two HPV viruses contained in the vaccine was 92.9%.

How long does vaccine protection last? Will a booster shot be needed?
The length of immunity is usually not known when a vaccine is first introduced. So far, studies have shown women to still be protected after five years. More research is being done to find out how long protection will last, and if a booster dose will eventually be needed.

Who recommends this vaccine?
The Centers for Disease Control and Prevention (CDC), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP) all recommend HPV vaccination in females. The vaccine is also recommended by the American Cancer Society for use in females ages 9 through 18 years. The CDC has issued permissive use of HPV4 (Gardasil) in males ages 9 through 26 years to reduce their likelihood of acquiring genital warts; CDC does not recommend HPV4 for routine use among males.

How safe is this vaccine?
The HPV vaccine has been tested in nearly 40,000 females (age 9-26 years) and over 4,000 males in many countries around the world, including the United States. These studies found that the HPV vaccine was safe and caused no serious side effects. A post-licensure safety monitoring plan is in place.

What side effects have been reported with this vaccine?
Mild problems may occur with HPV vaccine, including pain at the injection site (8 people in 10), redness or swelling at injection site (1 person in 4), mild fever (1 person in 10), itching at the injection site (1 person in 30), moderate fever (102°F) (1 person in 65). These symptoms do not last long and go away on their own. Fainting has been reported among adolescents who receive HPV vaccine (and other recommended vaccines as well). It's best for the patient to sit during vaccine administration and then wait at the clinic for 15-20 minutes after getting vaccinated.

Like all vaccines, HPV vaccine will be monitored for more serious or unusual side effects.

We've heard stories in the media lately about severe reactions to the HPV vaccine. Is there any substance to these stories?
No. In summer 2008 some concerns were raised over two issues--reports of deaths and reports of Guillain-Barré syndrome (GBS) reported to the Vaccine Adverse Events Reporting System (VAERS) following vaccination with Gardasil. CDC reported that there was not a common pattern to the deaths; if there had been a common pattern, it would suggest the deaths might be caused by the vaccine. FDA and CDC reviewed the reports and found no evidence that Gardasil increased the rate of GBS above what is expected in the population. CDC, working with the FDA and other immunization partners, will continue to monitor the safety of Gardasil. You can find complete information on this and other vaccine safety issues at www.cdc.gov/vaccinesafety.

Do women still need to get a Pap test if they've been vaccinated against HPV?
Yes! Women should continue to receive regular cervical cancer screening for three reasons. First, the vaccine does not provide protection against all types of HPV that cause cervical cancer. Second, women may not receive the full benefits of the vaccine if they do not complete the vaccine series. Third, women may not receive the full benefits of the vaccine if they receive the vaccine after they have already acquired HPV infection from one of the four types for which the vaccine is preventive.

In addition, vaccinated women should continue to practice protective sexual behaviors since the vaccine will not prevent all cases of genital warts or other sexually transmitted infections.

Does the vaccine protect against all types of HPV?
No, although there are more than 100 types of human papillomaviruses, only four (HPV 6, 11, 16, and 18) are covered in the Gardasil vaccine and only two (HPV 16 and 18) are covered in the Cervarix vaccine. HPV 16 and 18, however, are responsible for 70% of cervical cancers; HPV 6 and 11 cause approximately 90% of genital warts. Because there will be 30% of cervical cancers not prevented by the vaccine, it is important for women to continue getting regular Pap tests.

What if a person doesn't get all of the recommended three doses?
It is not yet known how much protection girls/women would get from receiving only one or two doses of the vaccine. For this reason, it is very important that individuals get all three doses of the vaccine. If there is a gap in the schedule longer than the recommended time, the series should just be continued from where it left off—there is no need to start the series over. A woman can and should complete the series even if she is older than age 26 years.

Do women whose sexual preference is women need HPV vaccine?
Yes. Eligibility for HPV vaccine is not determined by sexual preference.

Who should NOT receive HPV vaccine?
Anyone who has ever had a life-threatening allergic reaction to yeast, any other component of HPV vaccine, or to a previous dose of HPV vaccine, should not get the vaccine.

Pregnant women should not get the vaccine. Although the vaccine appears to be safe for both the mother and developing baby, this issue is still being studied. Inadvertently receiving HPV vaccine during pregnancy is not a reason to consider terminating the pregnancy. Any woman who learns she was pregnant when she got the HPV vaccine is encouraged to call the HPV Vaccine in Pregnancy Registry at either (800) 986-8999 for the Gardasil vaccine or (888) 452-9622 for the Cervarix vaccine. Information gathered from this registry will help experts learn how pregnant women respond to the vaccine.

Breast-feeding women can safely get the vaccine.

Persons who are moderately or severely ill should wait until their condition improves to be vaccinated.

Will the vaccine be covered by insurance plans?
Most insurance plans and managed care plans cover recommended vaccines for children. However, there may be a lag time after a vaccine is recommended before it is available and covered by health plans.

The Vaccines for Children program provides free vaccines to children and adolescents younger than 19 years of age, who are either Medicaid-eligible, American Indian, or Alaska Native, uninsured, or receiving care in a Federally Qualified Health Clinic or Rural Health Center. This includes boys as well as girls.

Can the vaccine cause HPV?
No. The vaccine is inactivated so it cannot cause disease-like symptoms or HPV disease.

Questions and answers about HPV disease

Technically reviewed by the Centers for Disease Control and Prevention, July 2010