Of U.S. women and girls ages 14 to 59, about 24.9 million women, or 26.8%, have the human papillomavirus, and about 2% of women and girls in the age group have HPV strains 16 or 18, which together cause about 70% of cervical cancer cases, according to a study published in the Feb. 28 issue of the Journal of the American Medical Association, the Wall Street Journal reports (Naik, Wall Street Journal, 2/28).
For the study, Elieen Dunne, a CDC epidemiologist, and colleagues analyzed data from the 2003-2004 National Health and Nutrition Examination Survey, which collected vaginal swabs and demographic information from 2,026 women ages 14 to 59. The study found that HPV prevalence is 44.8% among women ages 20 to 24, 27.4% of women ages 25 to 29, 24.5% among women and girls ages 14 to 19, and 19.6% among women ages 50 to 59 (Gellene, Los Angeles Times, 2/28). The study also found that about 3.4% of participants, or 3.1 million women, had one of the four strains of HPV that Merck's HPV vaccine Gardasil protects against (Wall Street Journal, 2/28). Gardasil in clinical trials has been shown to be 100% effective in preventing infection with HPV strains 16 and 18. According to Merck, Gardasil is about 99% effective in preventing HPV strains 6 and 11, which together with strains 16 and 18 cause about 90% of genital wart cases. Gardasil also protects against vaginal and vulvar cancers, two other gynecological cancers that are linked to HPV, according to a study presented in June 2006 at a meeting of the American Society of Clinical Oncology in Atlanta. FDA in July 2006 approved Gardasil for sale and marketing to girls and women ages nine to 26, and CDC's Advisory Committee on Immunization Practices later that month voted unanimously to recommend that girls ages 11 and 12 receive the vaccine (Kaiser Daily Women's Health Policy Report, 2/22). According to the Journal, because about 90% of women infected with HPV are cleared of the virus within two years, the prevalence data in the study is limited because it does not include cleared HPV infections.
Dunne said that the study findings do not indicate an increase in HPV prevalence, only that HPV prevalence is greater than previous estimates. Dunne said that "it's just a different measurement -- and a more accurate one"(Brown, Washington Post, 2/28). Richard Haupt, executive director of medical affairs in Merck's vaccine division, said that although prevalence of the HPV strains Gardasil protects against are relatively low, there still are "many women who will benefit from being protected" by Gardasil (Wall Street Journal, 2/28). Dunne said that the vaccine is vital and that the 3.4% prevalence for the four strains Gardasil protects against found in the study "is a snapshot." She added, "Over their lifetimes, a lot more than 3.4% of women may develop the strains that the vaccine protects against. They might have more exposure, new partners" (Tasker, Miami Herald, 2/28).
Gardasil Trials Halted Because of High Efficacy
In related news, two clinical trials of Gardasil were stopped earlier than planned due to the high efficacy of the vaccine, Sanofi Pasteur, a joint company of Merck and Sanofi-Aventis, announced on Tuesday, Dow Jones reports (Berton, Dow Jones, 2/27). The trials were halted after an independent Data and Safety Monitoring Board recommended the trials end on ethical grounds so that participants receiving a placebo could receive Gardasil, Reuters reports (Reuters, 2/27). Study centers in Europe have already begun vaccinating women who were receiving a placebo, and vaccination is expected to begin during the next few weeks in other countries (Berton, Dow Jones, 2/27).
The JAMA study is available online.
Three broadcast programs reported on the study:
- ABC's "Good Morning America": The segment includes comments from Nancy Chescheir, chair of the Department of Obstetrics and Gynecology at the Vanderbilt University School of Medicine (McKenzie, "Good Morning America," ABC, 2/28). Video of the segment is available online. Expanded ABC News coverage also is available online.
- NBC's "Nightly News": The segment includes comments from Dunne and Richard Friedman, a gynecological oncologist (Snyderman, "Nightly News," NBC, 2/27). Video of the segment is available online.
- PBS' "NewsHour with Jim Lehrer": The segment includes a discussion with Susan Dentzer, health correspondent for "NewsHour with Jim Lehrer." In addition, the segment includes a discussion with Ralph Anderson, chair of the Department of Obstetrics and Gynecology at the University of North Texas Health Center, and Wendy Wright, president of Concerned Women for America (Woodruff, "NewsHour with Jim Lehrer," PBS, 2/27). Audio and a transcript of the segment are available online.
This article was reprinted from khn.org with permission from the Henry J. Kaiser Family Foundation. Kaiser Health News, an editorially independent news service, is a program of the Kaiser Family Foundation, a nonpartisan health care policy research organization unaffiliated with Kaiser Permanente.