Who Should Get the HPV Vaccine and When?

Should governments and school systems require girls and young women to get the human papillomavirus (HPV) vaccine, which helps prevent cervical cancer? A new study in the Aug. 21 edition of the New England Journal of Medicine (NEJM), examining the cost-effectiveness of the vaccine for 12-year-old girls versus young women, is adding fuel to the debate.

Pharmaceutical company Merck got FDA approval in June 2006 to market the vaccine, Gardasil, to females ages 9 to 26. Millions of girls have been vaccinated since then, but not without controversy over the idea of immunizing young girls against a virus that is sexually transmitted. (The vaccine protects against the two types of HPV that cause 70 percent of cervical cancer worldwide, and against forms of the virus that cause 90 percent of genital warts in both men and women.) Another point of contention has been the vaccine's cost--about $360 for three shots taken over six months. This week's NEJM report indicates that the vaccine appeared to be cost-effective for 12-year-olds, assuming that immunity doesn't wane after 10 years; in that case, a booster shot would be required. It also found that "catch-up" programs for 20-somethings may be too expensive.

An NEJM editorial accompanying the study raises other questions about whether the vaccine provides lifelong protection from the virus and whether it should be required by public health officials. "This is still an experiment. And it should be treated that way," says Charlotte Haug, editor in chief of the Journal of the Norwegian Medical Association and author of the NEJM editorial. "There are good reasons to take a deep breath and keep doing the research."

Karen Springen spoke with study co-author Jane Kim, assistant professor of health-decision science at the Harvard School of Public Health, about why there is so much conflicting information about how the HPV vaccine should be used, and what researchers still don't know about it. Excerpts:

NEWSWEEK: What's your recommendation for parents of young girls who are considering the vaccine?
Jane Kim:
This type of analysis is not really equipped to help inform individual decision-making. What we're trying to do is help policy decision making. From a population standpoint, we found that vaccinating preadolescent girls, prior to sexual activity, is a good value for the money.

It seems it may not be as cost-effective to vaccinate older girls who are already sexually active. Why not?
The vaccine is not beneficial for women who already have HPV. Once you start sexual activity, HPV is so prevalent. We're looking at a whole population of 26-year-olds. At that age, most females are sexually active. Their chances of having been exposed to one of the [virus] types increases with age. We find diminishing health benefits.

Couldn't women get a test to see if they had already been infected with HPV types 6, 11, 16 and 18, which Merck's vaccine protects against?
The clinical test that's used right now for screening does not tell you which particular types you have. It wouldn't really be applicable.

Is the test expensive?
I think it's about $48 just for the test. It tells you if you have high-risk HPV, but there are 15 types [that increase the risks of cervical cancer]. It can't tell you [exactly] what type you have. There are lab tests, pretty sophisticated lab essays--but we don't use that in clinical practice.

The vaccine has FDA approval for girls as young as 9. Is that too young? 
We have no idea about the duration of protection. It could be that maybe 9 is too young. We can't know for sure. The pharmaceutical companies are going to continue to monitor that to see how long we can expect the protection to last.

Should they be reconsidering the age recommendations based on the findings of your study?
I don't think people are planning on revisiting the current recommendations. But ... Merck is seeking approval for vaccinating up to age 45. Our study has implications for that policy.

Wouldn't vaccinating older women make very little sense, unless the woman was a 45-year-old who'd never been sexually active?
The implication from our study, that could be extrapolated, is that the cost-effectiveness really diminishes with age. That's not to say that there aren't 40-year-old women who wouldn't benefit, but from a population standpoint, we think the older the population is, the less cost-effective it is.

You get no payment from the drug companies, correct?
No.

What do you think about criticism that Merck is promoting the drug too much?
It's a double-edged sword. The article [in today's New York Times] displays a healthy level of skepticism [about] whether or not there are explicit or implicit incentives to promote this vaccine beyond the health implications of the population. I don't want to comment on whether or not it's tipped that scale, but I think for sure there's a danger there. Which is why we, as academics, have tried to really veer away from any kind of link to industry when we're doing this kind of work. We don't want to be perceived as remotely having any kind of incentive to promote this product.

With people who do get endorsements and speaker fees from the pharmaceutical companies, it's not that there's necessarily ill intent. It's hard to disentangle. You can't divorce the industry from the science because they're the ones who produce it. There's a slippery slope when it comes to marketing and promoting, and education.

What should the public know about the vaccine that may not be coming across in the coverage of the issue?
Women need to continue to get screened with the Pap smear or a screening technology, including the HPV DNA test. The vaccine is targeting two of many different types that can cause cervical cancer. We can't stop screening. This isn't the panacea against cervical cancer. It's really helpful, but we need to continue screening.

If you had daughters, at what age would you get them vaccinated?
I don't want to comment on that. That brings in not only science, but philosophical, religious beliefs.

What are implications for the rest of the world, where cervical cancer is more prevalent? [In the United States last year, an estimated 11,150 women developed cervical cancer and 3,600 died from it.]
It's a much bigger deal in other parts of the world. This is where the burden is the highest--in countries in Africa and Southeast Asia. It has huge implications. It's expensive. At the current price, it's way too expensive for these countries that have GDPs that are a fraction of what we have in the United States. From a public-health perspective, it's a great opportunity to promote cervical cancer prevention. It would be a shame if money was the deterrent, but it's very expensive.

What's the next line of research on the HPV vaccine?
We need more time to know how long it's effective. We'd love to know if it's efficacious in boys. Does it help prevent other health conditions?

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