Cervical cancer shots less cost-effective with age

August 20, 2008 8:47:57 PM PDT
A prominent medical journal has raised big questions about whether a cervical cancer vaccine given to millions of girls is effective. And since Gardasil was approved only two years ago, the long-term effects are not known.

Shannon Nelson is now working in Wrigleyville. The 19-year-old says she is finally moving again after getting the Gardasil vaccine in June of 2007.

"When I was in the hospital, I lost my facial expressions. Losing my smile was the worst because I like to smile a lot," Nelson said.

Gardasil is the cervical cancer vaccine. More than 8 million girls and young women have been vaccinated since 2006. Nelson says she survived serious side effects, including Guillaine Barre Syndrome that results in paralysis.

"You trust your doctor. You trust your parents, and it sounded like a good idea to be protected," Nelson said.

But now, a study published in the New England Journal of Medicine points out that Gardasil is unproven. Cervical cancer takes years to develop, so it will take time to research its long-term effectiveness. And critics blame federal agencies for side effect dangers, including the Food and Drug Administration.

"I think the FDA and CDC have to do a better job of doing safety before vaccines go on the market," said Barbara Mullarkey, Illinois Vaccine Awareness Coalition.

FDA records reveal that since Gardasil was approved, nearly 9,000 girls suffered from "bad health events" after their shots, including 78 outbreaks of genital warts. Eighteen deaths and six cases of Guillan-Barre Syndrome have also been reported.

But Merck, the company that makes the vaccine, says it's been studied in 25,000 women and is safe.

"These reports of conditions that have occurred do not mean they are related," said Rick Haupt, executive director of Merck Research.

In fact, Dr. Yvonne Collins, a member of an Illinois Task Force to eliminate cervical cancer, says even though the controversy will continue, she strongly recommends the vaccine.

"We don't know the complete benefit. What if it ends up being significantly more beneficial than we think it is? Right now, it appears to be 100 percent effective in preventing cancerous lesions and prevention of cancer, especially cervical cancer," Collins said.

Read the full article from the New England Journal of Medicine.

The vaccine against the HPV virus was licensed in 2006 for use in girls and women ages 9 to 26. Health officials recommend it for girls at age 11 or 12, and some doctors offer it to women in their 20s in "catch-up" vaccination campaigns.

The maker of the Gardasil vaccine, Merck & Co., also wants to market it to women ages 27 to 45, but so far the U.S. Food and Drug Administration has denied that request.

The government-funded study found the HPV vaccine is very cost-effective when given to girls at age 12, but raises questions about the value of pushing for vaccinating adults.

Two researchers at the Harvard School of Public Health did the study, one of the most sophisticated analyses of the issue so far. Results are in Thursday's New England Journal of Medicine.

Gardasil is given in three doses over six months and costs about $375. It targets the two types of HPV, or human papillomavirus, believed to be responsible for about 70 percent of cervical cancer cases, and two other types that cause most genital warts. The virus spreads through sex.

Health officials say it's best to give the shots to girls at age 11 or 12, before they begin having sex. Some parents think that age is too young for a vaccination campaign against a sexually transmitted disease.

But that is when the shots make the most economic sense, the researchers found.

They used computer models to predict the health outcomes of girls and women who get the vaccination as well as Pap tests or other screenings, which are still recommended for vaccine recipients. Their calculation included the cost of the vaccine, screenings and treating cervical cancer and other illnesses targeted by the vaccine.

To determine cost-effectiveness, the researchers used widely accepted economic measures of how much society is willing to pay to extend the life of a person by a year. They set a figure of $43,600 per year for the Gardasil vaccination of each 12-year-old girl, well below the $100,000 mark seen as an upper range for cost-effectiveness.

That assumes the vaccine gives lifetime protection -- something doctors don't know is true, because the shot is too new.

"Their base-case assumptions are quite optimistic," wrote Dr. Charlotte Haug, a Norwegian physician, in an editorial that accompanies the study.

The figure would rise if a booster shot is needed, but would still be under the cost-effective threshold, experts said. Another caveat: Costs could rise if there is an increase in the types of cancer-causing HPV not included in the vaccine.

Vaccinating "catch-up" campaigns for women in their 20's, however, would not be cost-effective, the researchers said. They didn't calculate cost-effectiveness of vaccinating women ages 27 to 45, but a trend seems clear, said Jane Kim, the study's lead author.

"As you get older, the vaccine becomes less cost-effective," she said.

Experts believe that the earlier a female is vaccinated, the better the odds she will avoid HPV-caused cervical disease, thus lowering health-care costs down the road.

Even though Merck can't promote its use for them, women older than 26 can get the shot from their doctors, as part of an "off-label" use. An individual woman may decide that getting vaccinated is worth it even if vaccinating everyone her age isn't considered cost-effective, some policy experts noted.

Many women in their 30s and 40s have not been exposed to the HPV types in the vaccine and could benefit from the shots, said Dr. Richard Haupt, Merck's executive director for Gardasil research.

GlaxoSmithKline PLC has developed another HPV vaccine, called Cervarix, which it sells in other countries. That vaccine has not yet been approved for the U.S. market.


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