By Erik Ness
Worth the Cost?
Some researchers voice concern over HPV vaccinations
By Erik Ness
A day after Harald zur Hausen won the 2008 Nobel Prize in Physiology or Medicine for his discovery that human papillomavirus (HPV) causes cervical cancer, the German virologist fueled the continuing debate on HPV vaccines. Speaking to the German newspaper Frankfurter Rundschau, on Oct. 7, 2008, zur Hausen declared that Gardasil and Cervarix—the vaccines developed to protect against the types of HPV that cause most cervical cancers—are “far too expensive.”
The Nobel capped a busy two months for HPV in the newsroom. On Aug. 20, 2008, the New York Times published a major story that contrasted the marketing ascent of the HPV vaccine with concerns it is being adopted too rapidly. One day later, the New England Journal of Medicine (NEJM) published a study on the economic implications of the vaccine.
Gardasil, sold by Merck, was approved by the U.S. Food and Drug Administration (FDA) in June 2006, and Cervarix, made by GlaxoSmithKline, is not yet FDA-approved, but is available in Australia and the European Union.
The debate revolves around two questions: Is vaccination worth the cost—about $360 for Gardasil’s three required shots—and do we know enough to justify large-scale use. The NEJM study, conducted by Harvard School of Public Health researchers Jane J. Kim and Sue J. Goldie, used complex modeling to project that HPV vaccination could lower cervical cancer rates in an economical way if the vaccine uptake is high among 12-year-old girls—its target group—and if the vaccine’s protection against infection lasts for their lifetimes. Currently, the Centers for Disease Control and Prevention (CDC) recommends “catch-up” vaccines for 13- to 26-year-olds, but Kim and Goldie found that catch-up vaccination may not make economic sense for older teens or women in their 20s.
The two researchers also pointed to the importance of long-lasting vaccine-induced immunity, wide vaccination among pre-adolescent girls, as well as Pap screening for cervical cancer beginning in the early to mid-20s. Both authors declined to elaborate on their research for CR.
When considering the vaccine, “People are beginning to doubt a little more that this is a good thing,” says immunologist Charlotte J. Haug, the editor of the Journal of the Norwegian Medical Association, who penned an editorial accompanying the NEJM study. “I don’t think we have enough evidence. It’s a very promising thing, but I cannot see why we shouldn’t get some more answers before we start large-scale vaccination of completely healthy girls.” So far, 1 in 4 adolescents in the U.S. has received at least one dose of Gardasil, according to a report released in October by the CDC.
Among the major unanswered questions, she says, is what will happen to the natural mix of HPV types after the vaccines start to take hold in the population. Gardasil and Cervarix each protect against only four of scores of types of HPV. “Here we have at least 20 other very similar strains, very prevalent, all over the place. It’s absolutely certain that they will come and take the place of HPV 16 and 18,” the two types most commonly linked to cervical cancer, says Haug. “The only question is will they be more or less oncogenic” than their predecessors.
The NEJM study shows that how long the vaccine lasts is key to deciding if it’s cost-effective, according to Dartmouth Medical School’s Diane Harper, a cervical health specialist who participated in clinical studies of the vaccines. “As excited as I am about the vaccine, and as much good as I think it will do, I think it’s been oversold,” she says.
“We have to understand that the vaccine is not going to eliminate cervical cancer,” she adds, “and that we don’t really know how long it’s going to last.”