• Mayo Clinic Q and A: HPV Vaccination Series Can Be Started at Age 9

a group of tweens - boys and girls

DEAR MAYO CLINIC: What is the best age for boys and girls to get the human papillomavirus, or HPV, vaccine? There seems to be a range, but I have read recommendations where that range differs. Is it true that if they don’t get the vaccine by a certain age, they are better off waiting until their 20s? Finally, what are the known side effects of the vaccine?

ANSWER: The HPV vaccine is a safe and effective vaccine that prevents some types of cancer. The best time for boys and girls to get the vaccine is before they are exposed to the virus. The vaccine is available for kids and is routinely given starting at age 9. It can safely be given between the ages of 9 and 26. There is not a medical reason that patients need to wait until their 20s to get the vaccine. Side effects are uncommon and generally mild, including pain at the site of the injection.

HPV is the most common sexually transmitted infection in the U.S. An estimated 14 million people get the infection every year. Although most cases of HPV are asymptomatic, HPV is a dangerous sexually transmitted virus that can be deadly. Two strains of the virus cause 70 percent of all cervical cancer. Cervical cancer can be difficult to treat, and it is often life-threatening. HPV infections also can lead to other genital and anal cancers in females, as well as penile cancer and anal cancer in males. In addition, HPV causes genital warts in both men and women.

The HPV vaccine has proven to be an effective way to prevent HPV infection. The vaccine is given as a series of three injections over six months. To be effective, a person needs to receive all three doses of the vaccine before being exposed to HPV infection.

The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommends the HPV vaccine for girls 11 to 12 years old. The vaccination series can be started at age 9. The vaccine also is recommended for females 13 through 26 who have not been vaccinated. The recommendation includes both the HPV2 vaccine (marketed under the brand name Cervarix) and the HPV4 vaccine (brand name Gardasil).

The ACIP recommends HPV4 vaccine for boys ages 11 to 12. Again, the vaccination series can be started at 9. The recommendation also includes males 13 through 21 who have not been vaccinated. The recommendation for boys includes only the HPV4 vaccine (Gardasil), as it covers two types of HPV that cause genital warts. The HPV2 vaccine only covers those that cause cancer.

Side effects of the HPV vaccine are typically mild. Common side effects include pain, swelling, or redness at the vaccination site. Less common are headaches and a low-grade fever after the injection. The HPV2 vaccine also may cause nausea, vomiting, diarrhea or abdominal pain. Although it is not common, HPV vaccination may result in fainting in some people. Because of this, when children receive the vaccine, they should remain seated for about 15 minutes after the injection to lower the risk of harm from fainting. They also should tell their health care provider if they feel faint.

Despite these mild side effects, the vaccine has been proven to be safe and was evaluated by the U.S. Food and Drug Administration (FDA). Millions of doses of the vaccine have been given and closely monitored. A wealth of data supports the safety and effectiveness of the HPV vaccine. It can protect against a deadly form of cancer. Giving children the HPV vaccine is a critical step in ensuring their long-term health. Dr. Rachel Lynch, Community Pediatrics and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota

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