Cervical Cancer Vaccine Benefit Lasts

Studies Show Long-Term Protection From Gardasil and Cervarix

From the WebMD Archives

April 17, 2007 (Los Angeles) -- Two vaccines for preventing cervical cancer, one that is already available and another that is undergoing FDA review, continue to offer nearly 100% protection five years following administration, new research shows.

The findings come at a time when use of the vaccines is being hotly debated, with states grappling with the issue of access to a vaccine for a sexually transmitted disease.

Darron R. Brown, MD, professor of medicine, microbiology, and immunology at the Indiana University School of Medicine in Indianapolis, says the durability of the protection is an important issue.

"Right now, the data suggest strong sustainability with either vaccine. We don't know if a booster will be needed, but from what we're seeing, I think the vaccines will provide protection for a lifetime," he tells WebMD.

The vaccines were discussed at the annual meeting of the American Association for Cancer Research.

Cervical Cancer Vaccines Target HPV

Both vaccines protect against cervical cancer by preventing infection with two strains of human papillomavirus (HPV) -- 16 and 18 -- that are responsible for up to 70% of all cervical cancers.

Gardasil, the approved vaccine, also targets HPV 6 and 11, which account for 90% of genital warts -- providing the woman has not been previously exposed.

HPV is a sexually transmitted virus, with dozens of strains.

The University of Louisville's Stanley Gall, MD, who tested Cervarix, the vaccine under review, predicts it will be approved soon. Then it will be up to each person to decide which one fits her needs, he says.

"They're both wonderful products and the family and their doctor will have to decide which is best," he tells WebMD.

Gall says that younger people are more likely to develop genital warts, so they might decide to opt for the additional protection offered by Gardasil.

Cervical Cancer Vaccine Debate Heats Up

The big, looming issue will not be which vaccine to get, but whether to get it at all, he says. "If we don't get it into people, they won't benefit," he says.

The FDA approved Gardasil for girls and women aged 9-26. The CDC recommends the vaccine to girls 11-12 years old, but it can be given to girls as young as 9. The CDC also recommends it for 13- to 26-year-old females who haven't already received or completed the vaccine series.

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Texas is the only state to mandate the vaccine. Debates in several states on whether to join it have been faced with a backlash, with critics charging that the vaccine promotes promiscuity and denies parents their rights.

Gall, who backs state mandates, says the backlash is appalling given that more than 11,000 new cases of cervical cancer will be diagnosed in 2007, with more than 3,600 deaths, according to figures from the American Cancer Society.

"Patients are always asking, 'Why isn't there a vaccine to prevent cancer?' Well, now you have a cancer vaccine. The whole idea is to use it," he says.

Gall also thinks states should offer the vaccine for free. "This would really help us make headway in getting into the population that needs it," he says.

Brown says he doesn't support mandates. "What we need to do is educate families about the high level of safety and effectiveness of the vaccine. Once they understand that, I think very few would not want their daughters to be immunized," he says.

Noting that Gardasil is also being tested in males -- who spread HPV to their sexual partners - Brown says, "If we ever get FDA approval for use in males, I'd make sure my boy got it."

Duke University's H. Kim Lyerly, MD, moderator of a news conference on the findings, says the medical community is still trying to figure out whether state mandates or education is the best way to ensure all girls get vaccinated.

Vaccines Protect Against Other HPV Subtypes, Too

The new research presented at the meeting also showed that both Gardasil and Cervarix protect against HPV types 45 and 31, which are together responsible for 10% of cervical cancers, Gall says.

"It's not a surprise that the vaccine offers protection against additional types of HPV, as they are all related genetically," he explains.

Both vaccines also appeared to prevent abnormal, precancerous cell growths found in the cervix, he says.

The Cervarix study, funded by GlaxoSmithKline, which makes the vaccine, included 1,113 women aged 15 to 25 in North America and Brazil who were given either three doses of the vaccine or a placebo.

The Gardasil study, sponsored by maker Merck & Co., involved 12,167 women aged 16 to 23.

WebMD Health News Reviewed by Louise Chang, MD on April 17, 2007

Sources

SOURCES: Darron R. Brown, MD, professor of medicine, microbiology and immunology, Indiana University School of Medicine, Indianapolis. Stanley Gall, professor of obstetrics and gynecology, University of Louisville. H. Kim Lyerly, MD, Duke University, Durham, N.C. American Cancer Society.

© 2007 WebMD, Inc. All rights reserved.

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