An Interview with Rachel A. Katzenellenbogen, MD During Cervical Cancer Awareness Month in January

Can you describe the relationship between cervical cancer and HPV (human papillomavirus)?

There are well over 200 known types of HPVs, and it is a very common infection. A subset of them, called high-risk HPVs, are associated with cancers that can result from a long-term infection. There are more than a dozen high-risk HPVs, which cause nearly 100 percent of all cervical cancers. In addition, HPV is associated with head and neck cancer (and other cancers) that can be inhibited by the vaccine.

Who is the HPV vaccine for and when should it be administered? How difficult is it to persuade parents, and is their permission essential?

The HPV vaccine is approved for all people between the ages of 9 to 45. The recommended age to receive the vaccine in the U.S. is 11 to 12 years old, but the vaccine series can be administered as young as 9. The HPV vaccine protects a person from HPV infection, so it is critical to get vaccinated before you are exposed. The vaccine does not treat HPV after infection. Since 75 percent of people have evidence of a current or prior infection with HPV, it is important to be vaccinated at a young age. We are all at risk, but infections can be prevented.

I think all parents want to protect their children from disease, especially cancer. This is a vaccine that can really wipe cervical cancers off the map, as well as other cancers that are increasingly common in men. Almost 5 percent of cancers worldwide are caused by HPV, so protecting against it can have a real impact on our children’s lives. The vaccine includes only one piece of HPV, not the whole virus, and it also does not contain any of the viral genes or proteins that cause cancer to occur. The vaccine is much safer than getting infected. I think this type of information is really helpful for parents to understand.

Parents do need to give permission for their minor children to receive preventive vaccines in the U.S.

How effective is the vaccine?

The current vaccine in the U.S. protects people against nine different types of HPV, seven of which are associated with cervical and other cancers. The vaccine is very effective in protecting someone from getting infected, having a long-term infection, or developing cancers. Also, the vaccine produces much higher, and more long-lasting, antibodies to HPV than an infection does. So far, we have not seen breakthrough infections that would signal the need for a booster shot – and people in these studies have been followed for more than 15 years. The antibodies that a person produces is also inversely related a person’s age. The younger you are when you get your HPV vaccines the better protected you are.

Are there side effects?

The more common side effects of the HPV vaccine are similar to those of other vaccines, including pain at the injection site, headache, fever or fatigue. An allergic

reaction is very rare. There are no other long-term side effects that have been associated with the HPV vaccine in studies that reviewed the tens of millions of doses distributed in the U.S. and worldwide.