Background

Vaccines have been developed that can help protect women from some HPV infections. So far, a vaccine that protects against HPV types 6, 11, 16, and 18 (Gardasil^®) and one that protects against types 16 and 18 (Cervarix^®) have been studied. In clinical trials, both vaccines prevented pre-cancer cervix cell changes caused by types 16 and 18; Gardasil^® also prevented genital warts caused by HPV types 6 and 11.

Gardasil^® is the only FDA-approved HPV vaccine available at this time. The vaccine is used to prevent HPV infection -- before an abnormal Pap test develops. It will not treat or protect against an existing infection. The Gardasil^® vaccine requires a series of 3 injections over a 6-month period. The second injection is given 2 months after the first, and the third is given 4 months after the second.

American Cancer Society recommendations

• Routine HPV vaccination is recommended for girls 11 to 12 years old.

• Girls as young as age 9 can get HPV vaccination.

• HPV vaccination is also recommended for females 13 to 18 years old to catch up missed vaccines or to complete the series.

This means that girls in this age group who have not yet started the series of vaccinations and those who started before age 13 but have not yet completed the vaccination series should be vaccinated.

• At this time there is not enough evidence to recommend for or against vaccinating all 19- to 26-year-old females in the general population. A decision about whether a woman aged 19 to 26 years should get the vaccine should be based on an informed discussion between the woman and her health care provider. This discussion should include the likelihood of previous HPV exposure and potential benefit from vaccination. For the greatest benefit, the vaccine should be given before there is a possible exposure to genital HPV through sex. The more sexual partners a woman has had, the less likely the vaccine will be of benefit.

The lack of evidence for recommending vaccination for the 19 to 26-year old age group is based on the following:

• In clinical trials, women who had an average of 2 to 4 sexual partners before they got vaccinated got less benefit from the vaccine in terms of reducing the overall incidence of cervical cell changes. (The average number of sexual partners for women 19 to 26 is 3 to 4.)

• The vaccine has not been tested in women who have had more than 4 sexual partners.

• It is not known if vaccination is cost-effective in this age group.

• At this time vaccination is not recommended for women over age 26 or for males of any age. Research is now being done on using Gardasil^® in older females and in males.

• Vaccinated and unvaccinated women should continue to be screened for cervical cell changes with Pap tests and other tests, according to current ACS early detection guidelines.

The vaccine protects against 70% of cervical cancers but doesn't protect against all cancer-causing types of HPV, so even in women who have been vaccinated, cervical cancer is still possible.

Reference

Saslow D, Castle PE, Cox JT, et al. American Cancer Society guideline for human papillomavirus (HPV) vaccine use to prevent cervical cancer and its precursors. CA Cancer J Clin. 2007;57:7-28.

Revised: 04/09/2008