According to a report in today's issue of the Journal of the American Medical Association, about 25 million women ages 14-59 carry the human papillomavirus. This tally, the authors note, is "higher than previous estimates" -- about two-thirds higher, according to the Washington Post's calculations. (The report: Dunne et al., "Prevalence of HPV Infection Among Females in the United States.")
Prevalence increases yearly among women starting at age 14 and peaks at 45 percent among women 20 to 24. As the American Council on Science and Health puts it, "nearly 50% of American women can expect to be infected at some point in their lives." Yeah, they're rounding up, but still, that's a lot.
Of course, the majority of HPV strains are harmless, or relatively so. But as we've learned from our discussions about the HPV vaccine, Gardasil, certain strains are believed to cause 99 percent of cervical cancers. Says the ACSH: "Released on the heels of the heated debate surrounding the possibility of mandating Gardasil vaccinations in young girls, these numbers simply underscore the importance of this vaccine from a public health perspective." Indeed, one hopes that perceived overstepping by Merck, Gardasil's manufacturer (rumored to have inspired the epithet "HPV: Help Pay for Vioxx"), will not overshadow the importance of the vaccine itself. Planned Parenthood, for one, continues to support -- under specified conditions -- a school mandate for HPV immunization. The CDC recommends the vaccine for girls at 11 and 12, before (ideally) they're sexually active.
But what of us older folks? The CDC also recommends "catch-up" shots up to age 26 -- through the peak years identified in this study. Sure, but -- as one Broadsheet letter writer pointed out, it's not like all women magically quit having new partners on their 26th birthdays. Couldn't the vaccine help the (very roughly) half of women not yet infected -- but still at risk -- at that age? A related JAMA editorial (subscription required; reprint here) asks a similar question, suggesting that more research into the particular HPV strains common among women 26 and up will help determine to what degree the vaccine could help them.