By Drs. Sally Robinson and Keith Bly
In last week's column, we presented information and statistics about the human papillomaviruses infection. As promised, you will find some frequently asked questions that the U.S. Centers for Disease Control and Prevention has provided on its Web site about the safety of this vaccine below:

How long does vaccine protection last? Will a booster shot be needed?

The length of vaccine protection (immunity) is usually not known when a vaccine is first introduced. So far, studies have followed women for five years and found that women are still protected. More research is being done to find out how long protection will last and if a booster vaccine is needed years later.

What does the vaccine not protect against?

Because the vaccine does not protect against all types of HPV, it will not prevent all cases of cervical cancer or genital warts. About 30 percent of cervical cancers will not be prevented by the vaccine, so it will be important for women to continue getting screened for cervical cancer (regular Pap tests). Also, the vaccine does not prevent about 10 percent of genital warts - nor will it prevent other sexually transmitted infections. So it will still be important for sexually active adults to reduce exposure to HPV and other STIs.

Will girls and women be protected against HPV and related diseases, even if they don't get all three doses?

It is not yet known how much protection girls and women would get from receiving only one or two doses of the vaccine. For this reason, it is important that girls and women get all three doses of the vaccine.

How safe is this vaccine?

The FDA has licensed the HPV vaccine as safe and effective. This vaccine has been tested in more than 11,000 females (ages 9-26) around the world. These studies have shown no serious side effects. The most common side effect is soreness at the injection site. CDC, working with the U.S. Food and Drug Administration, will continue to monitor the safety of the vaccine after it is in general use.
What do girls and women need to know about this series of shots?

The HPV vaccine is given through a series of three shots during a six-month period. The second and third doses should be given two and six months (respectively) after the first dose.

Will girls and women who have been vaccinated still need cervical cancer screening?

Yes. There are three reasons why women will still need regular cervical cancer screening. First, the vaccine will not protect against all types of HPV that cause cervical cancer, so vaccinated women will still be at risk for some cancers. Second, some women may not get all required doses of the vaccine (or they may not get them at the right times), so they may not get the vaccine's full benefits. Third, women may not get the full benefit of the vaccine if they receive it after they've already acquired one of the four HPV types.

Most important for the concerned parent to remember is to bring questions to your physician or your child's pediatrician. They will have the most updated information about the HPV vaccine and will be happy to speak with you about these concerns.
Dr. Sally Robinson is a pediatrician in the division of children's special services at the University of Texas Medical Branch at Galveston. She teaches medical students about caring for children with chronic medical conditions. Dr. Keith Bly is a hospitalist and assistant professor of pediatrics at UTMB. This column is not intended to replace the advice of a physician.

The Your Health column is written by health and medical experts at the University of Texas Medical Branch at Galveston. The column focuses on topical health issues that we believe are of interest to your readers. It is e-mailed every Tuesday. If you have any questions about the column, or would like to suggest topics, please contact John Koloen, media relations specialist, at (409) 772-8790 or email