Wednesday, July 05, 2006

New HPV Vaccine Generates Moral and Cost Effectiveness Debate
By Julie McKeel

Gillian Sanders, PhD

Merck & Co.'s new Gardasil vaccine against the sexually transmitted human papillomavirus gained regulatory approval in June. It was priced at $360 for a three-shot regimen, making it one of the priciest vaccines now on the market.

The vaccine is intended for adolescent girls to reduce their risk of HPV-linked cervical cancer later in life. Opponents of the vaccine have argued that inoculating girls against a sexually transmitted disease might send the message that sexual activity is acceptable, thus sparking a moral debate.

The vaccine's high cost has added to the debate. Based on price alone, the cost to insurers and the government to immunize 12-year-old girls could run up to $700 million a year just for the vaccine.

However, according to the manufacturer, the vaccine's impact on the nation's health-care costs could be considered a bargain when compared with its potential positive impact on women's health. Based on some early studies, the frequency of abnormal pap smears could be reduced if added protection against cervical cancer were in place. However, other experts argue that more needs to be known about the vaccine before assuming that overall costs will be reduced. If booster shots are needed or if the vaccine is not widely adopted, the cost effectiveness of this measure will be called into question.

The DCRI's Dr. Gillian Sanders, a cost-effectiveness analyst, has conducted two HPV vaccine cost-effectiveness studies. Her analysis shows that when a vaccine's impact goes beyond just the people who are inoculated, only about 70% of girls need to be vaccinated to bring the rate of cervical cancer down significantly in the population as a whole.

While many nations, including England , Australia , and Canada , use cost-effectiveness information to help make coverage and pricing decisions about treatments, the U.S. tends not to use the information in formal reports. For instance, Medicare doesn't take costs into account in coverage decisions and neither does the government-run vaccine fund for uninsured children.

Cost-effectiveness calculations, however, can vary tremendously depending on what is included in the models. And some factors can't be predicted, such as whether another strain of HPV will develop if the current strains are eliminated. And no one knows just how long the vaccine will be effective. According to Merck, the latest data show that the vaccine is good for at least five years.

Typically, interventions under $50,000 to $100,000 per quality-adjusted life year are generally considered cost effective. Vaccines for measles and mumps are so cost effective they actually save money. However, according to health-services researchers, Pap smears, which test for early signs of cervical cancer, can cost from $150,000 to $1 million per quality-adjusted year of life saved if given annually rather than every 3 years.

At a recent meeting of the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices, the vaccine's cost effectiveness was discussed. The ACIP also considered whether girls and women should be vaccinated, the recommended ages for the shot, whether a booster is needed, and – of most interest to Merck -- whether the vaccination should be part of a routine immunization regimen.

Because the CDC's recommendations serve as best-practice guidelines for doctors, insurers often follow the CDC recommendations in covering the cost of vaccinations. Merck has been successful in winning recommendations for its childhood vaccines, but the Gardasil vaccine is unusual because it targets a young population in order to prevent a fairly rare cancer in the U.S. that usually doesn't strike until middle age or later.

HPV infection is a significant cause of cervical cancer, which each year is diagnosed in an estimated 9,700 women. By comparison, there are 215,000 breast-cancer diagnoses a year. Gardasil aims to prevent infection from four strains of the HPV virus, including two strains that are considered high-risk for cancer.