I discussed the so-called “cervical cancer vaccine,” a multivalent vaccine protective against several strains of the human papilloma virus previously here. In the new issue of the New England Journal of Medicine, there’s a
perspective on the vaccine, and issues surrounding it:
Genital HPV infection is common, with an estimated 6.2 million new infections each year in the United States. Although most infections are asymptomatic and transient, persistent infection with oncogenic HPV types is a serious health issue. Cervical cancer is the 11th most common cancer among women in the United States — with an estimated 10,370 new cases and 3710 deaths in 2005. There are racial and socioeconomic disparities; more than half of all cases occur in women who have never or rarely been screened. Among women in developing countries, where effective screening programs are often lacking, cervical cancer is the second most common cancer, and a leading cause of cancer-related death.
In the studies conducted so far, efficacy has been very high. There are still many unanswered questions–such as how long immunity will last, what age vaccination should begin, and of course, the cost–currently estimated at $300-$500 for the three-dose series (ouch). The middle question will be addressed shortly:
If Merck’s HPV vaccine is licensed, the ACIP will probably vote at a June meeting on whether to recommend routine vaccination at 11 to 12 years of age, in an effort to confer immunity before adolescents become sexually active. HPV infection is usually acquired soon after sexual activity begins, with a cumulative incidence of about 40 percent within 16 months. According to 2003 data from the Youth Risk Behavior Surveillance System, 7.4 percent of adolescents initiate sexual activity before 13 years of age, about one third of them by ninth grade, and about two thirds by the end of high school. If people are vaccinated before they have had sex, they should benefit irrespective of when they become sexually active.
Similarly, recommendations to vaccinate only girls or both sexes need to be ironed out.
Finally, many are worried about acceptance by parents. It has been argued that his vaccine would have the effect of making teens more likely to engage in sexual activity, or more careless about it (see quotes in this article, for instance). However, even groups that were reportedly opposed to it may relent:
At the February ACIP meeting, the conservative Family Research Council, which promotes abstinence before marriage and fidelity within marriage as the best way to prevent sexually transmitted diseases, distanced itself from suggestions that it opposed HPV vaccines. Calling such reports “false,” the council said it “would oppose any measures to legally require vaccination or to coerce parents into authorizing it” and that “there is no justification for any vaccination mandate as a condition of public school attendance. However, we do support the widespread distribution and use of vaccines against HPV.”
The article ends with a good dose of pragmatism:
The HPV vaccine is likely to be considerably more expensive than many recommended vaccines, and its benefits will not be fully apparent for decades. It will be far easier to recommend routine vaccination than to provide the resources for its routine use, in the United States and throughout the world.
It’s one thing to recommend what seems to be a safe and effective vaccine–it’s another to actually have the parent get their child an expensive injection that’s unlikely to show benefits for many years, especially if it comes to a choice between groceries for a few weeks or the vaccination series. I hope this will be included in insurance plans–prevention is always more cost-effective than treatment, even if the results aren’t realized for many years.
Image from http://www.inca.gov.br/cancer/imagens/hpv_fig1.jpg