Special to CNN.com
Gardasil, a vaccine that offers protection from the virus responsible for cervical cancer, will soon show up on the official childhood immunization schedule — and in doctor's offices. On June 29, 2006, the expert committee that guides U.S. vaccination policy called for the routine immunization of all 11- and 12-year-old girls and catch-up immunization for girls and women ages 13 to 26.
The recommendation from the national Advisory Committee on Immunization Practices (ACIP) comes three weeks after the Food and Drug Administration (FDA) approved Gardasil to protect girls and women between ages 9 and 26 from the types of human papillomavirus (HPV) that cause most cervical cancer.
The cervical cancer vaccine could prevent up to 70 percent of cases of cervical cancer. Since HPV spreads through sexual contact, the vaccine's manufacturer says the cervical cancer vaccine would be most effective if given to girls before they become sexually active.
Bobbie Gostout, M.D., an HPV infection expert and gynecologic surgeon at Mayo Clinic, Rochester, Minn., directed basic and clinical research related to the HPV virus and immune defenses that help to fight HPV infection. Mayo Clinic scientists also participated in early clinical trials testing HPV vaccines.
Here, Dr. Gostout provides insight into this important cervical cancer vaccine.
What's the significance of the cervical cancer vaccine?
This is the first vaccine ever designed to prevent a cancer. Cervical cancer afflicts many women. In the United States, about 10,000 new cases of cervical cancer are diagnosed annually. About 4,000 women die of cervical cancer each year. The impact of the cervical cancer vaccine in the United States will be tremendous.
Worldwide, the impact may be even greater. According to the World Health Organization, there were half a million new cases of cervical cancer in 2005. Cervical cancer typically ranks as one of the top two causes of cancer death in women.
The tragedy of cervical cancer is that it often strikes when a woman is still young. She may be trying to raise her family or maybe she hasn't had children yet. A diagnosis of cervical cancer often forces a woman to undergo treatment that makes future fertility impossible.
What does the cervical cancer vaccine do?
The cervical cancer vaccine blocks infection with human papillomavirus (HPV), a virus that causes cervical cancer. HPV spreads through sexual contact. This vaccine gets at the root cause of cancer and stops the cancer before even the first step can begin. The cervical cancer vaccine specifically blocks two cancer-causing types of HPV — types 16 and 18 — which are responsible for the majority of cases of cervical cancer.
Why should the vaccination be given at age 11 or 12?
By vaccinating within that age range, we're activating the immune systems of these girls before they're likely to encounter HPV. Vaccinating this age group also allows for the highest antibody levels — higher than if girls are vaccinated after age 15. Antibodies are proteins your immune system produces in response to a vaccine or infection and stores for when you next come into contact with that virus or other infectious agent.
The ACIP also recommended the vaccine for girls and women ages 13 to 26 who haven't received the vaccine already. By vaccinating this catch-up group, as well as the younger girls, we'll see the positive effects of the cervical cancer vaccine that much sooner.
If you're 26 or younger and you're already sexually active, can the vaccine be of benefit to you?
Yes, the cervical cancer vaccine provides protection to women who are 26 or younger but already sexually active. Included in the clinical trials of the vaccine was a group of women who were sexually active and who had already been infected with one or more of the vaccine HPV types. Researchers still observed a benefit of this vaccine in reducing disease in that group of women.
What's the dosing schedule of the cervical cancer vaccine?
The cervical cancer vaccine is administered by injection of three doses during a six-month period. You receive the first dose followed two months later by the second dose. Six months after the first dose you receive the third dose.
Why are three doses of the cervical cancer vaccine needed?
We really don't know that three doses are necessary because we don't know what antibody levels give adequate protection from HPV. In early clinical trials, researchers observed that the antibody levels in women continued to go up with each of the three doses of the vaccine. Since antibody levels inevitably fall once you stop getting a vaccine, it makes sense to start with high antibody levels to get the greatest HPV protection for the longest possible time — years or even decades.
Over time, we may find out that you really don't need three doses of the vaccine or we may discover that you need a booster years later. Those are details we just don't know right now. But so far, the vaccine has performed very well in women given three doses.
Does the vaccine carry any health risks or side effects?
With more than 25,000 women and girls vaccinated in programs so far, the cervical cancer vaccine has been remarkably safe. The most common complaint is soreness at the injection site — in the upper arm — which occurs in about eight out of 10 people who get the vaccine. Low-grade fever or flu-like symptoms also are common. But these have been mild enough that no one in the clinical trials discontinued the vaccination series because of side effects.
Will the cervical cancer vaccine be required for school enrollment?
Whether or not a vaccine becomes a requirement for school is decided on a state-by-state basis. However, if the cervical cancer vaccine remains optional, the vaccine won't become as widely used as it will be if it's made part of the routine childhood immunizations. Like vaccinating for illnesses such as influenza, mumps and chickenpox, people in the community get the best protection when a high percentage of the population is vaccinated. This vaccine is no different — the greater the number of girls and women vaccinated, the greater the benefit we'll see from the cervical cancer vaccine.
Will women still need to have Pap tests?
Absolutely. And this is a really important point. The cervical cancer vaccine isn't intended to replace Pap tests. Continue with routine screening for cervical cancer by getting regular pelvic exams and Pap tests.
What can you do to protect yourself from cervical cancer if you're not in the recommended vaccine age group?
The main protection you have against cervical cancer is participation in a regular screening program. Also, be aware of cervical cancer signs and symptoms:
* Vaginal bleeding after intercourse or between periods
* Vaginal bleeding after menopause
* Foul-smelling watery or bloody vaginal discharge
* Pelvic pain or pain during intercourse
Seek prompt medical attention if you notice anything unusual. And don't smoke. Smoking doubles your risk of cervical cancer.
How much will the cervical cancer vaccine cost?
The vaccine manufacturer estimates the series of three shots will cost between $300 and $500. Insurance companies will likely cover the expense of vaccination for girls and women in the recommended age groups — especially if the vaccine becomes mandatory — but that remains to be seen.
When will the cervical cancer vaccine become available?
The vaccine will probably be available — with the insurance issues ironed out — by late summer 2006.
Are there other cervical cancer vaccines in the works?
Yes, there's another cervical cancer vaccine — called Cervarix — in development. It's currently being considered for approval in Canada and Western Europe. The vaccine manufacturer plans to apply for vaccine approval in the United States later this year. Both Cervarix and Gardasil protect against HPV types 16 and 18. So at some point in 2007, we may have two vaccines available that offer protection from the virus that causes cervical cancer.
Tuesday, March 18, 2008