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Electronic letters published:
![[Read Comment]](/icons/misc/sectionDOWN.gif){kind=icon}
Before Counseling to Vaccinate, Know the facts about HPV
Understanding before Counseling
Understanding before Counseling
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Vera H Sharav, New York, USA Public Advocate for Accountability in Medicine
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The primary criticism of this study is the assumption—in the absence of scientific evidence—that the HPV vaccine is safe and effective in preventing cervical cancer. Serious concerns about the wisdom of mass vaccination of young girls have been raised by Dr. Diane Harper, the principle investigator of both Merck’s Gardasil, and GlaxoSmithKline’s HPV vaccine, and these concerns were validated in a critical editorial, “Private Wealth vs. Public Health,” in the Journal of the American Medical Association (JAMA, May 2007). http://jama.ama-assn.org/cgi/content/full/297/17/1921 Although the concerns were raised because of efforts—by Merck and the government--to mandate vaccination of young school girls, the issues raised should be of concern for primary care physicians. Indeed, the issues should be included in any counseling physicians undertake regarding the vaccine. The JAMA editorial cautions physicians against being swept up by unsubstantiated marketing hype, noting that the vaccine is supported by limited efficacy and safety data—and most HPV infections clear spontaneously within 6 months to 2 years. [1] [2]. Clinical trials have thus far involved a relatively small population (2 000 participants) for a limited period of follow-up (5 years). And, the vaccine has not been evaluated for efficacy among younger girls (aged 9 to 15 years). Given the evidence (or lack of evidence) JAMA advises, a clinician can honestly provide only the following information to a 12-year-old girl to obtain her assent: “The 3 injections will probably protect you from an infection that you can only get from sexual contact, but research has not shown how long the protection will last or whether it might have bad effects on your health." A new report by the Costa Rican HPV Vaccine Trial Group in JAMA (Aug. 15) sheds further light on the very limited potential benefit of the HPV vaccine (GSK version)—and on the fact that the U.S. government has a financial interest in the HPV vaccine—the government owns the patent. http://jama.ama-assn.org/cgi/reprint/298/7/743.pdf The study was conducted on 2,189 Costa Rican women aged 18 to 25 who had tested positive for HPV DNA at the time of recruitment. The study’s findings were negative: "There was no evidence of increased viral clearance at 6 or 12 months in the group who received HPV vaccine compared with the control group." What’s more, the safety issues of the vaccine remain unclear as the authors state, "we did not evaluate the safety profile of the vaccine in this analysis." References: 1. Ho GY, Bierman R, Beardsley L, et al. Natural history of cervicovaginal papillomavirus infection in young women. N Engl J Med. 1998;338:423-428. 2. Schiffman M, Herrero R, Desalle R, et al. The carcinogenicity of human papillomavirus types reflects viral evolution. Virology. 2005;337(1):76-84. Competing interests: No competing interests |
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Deborah L. Helitzer, Albuquerque, NM USA Professor and Vice Chair for Research, Department of Family and Community Medicine, U. New Mexico, Andrew L. Sussman
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We value Dr. Harper’s clarifications with regard to the efficacy of the HPV vaccine which clearly reflect the dynamic and evolving nature of scientific research in this area. It is important to note, however, that our article did not claim that the vaccine “must be given before initiation of sexual activity” but rather that doing so “will achieve the greatest benefit,” a position still consistent with current ACIP recommendations (1). Nevertheless, we were unaware of the vaccine’s efficacy in seropositive women and appreciate these points. The goal of this research was to explore the factors that influence cervical cancer prevention counseling in primary care settings. The economic modeling data provided by Dr. Harper emphasizes the importance of vaccinating the “catch up” group. It is interesting to consider whether women who have prior experience with Pap tests may be more receptive to the vaccine. However, given prior research suggesting a lack of understanding about HPV among adolescents and adults, and its relationship to Pap testing, it is not clear that uptake of the vaccine will be enhanced among these women (2). Given that females who receive the vaccine will continue to need regular Pap testing, these women might reject the vaccine as being unnecessary. Lastly, and perhaps most importantly, Dr. Harper’s insightful comments lead us to think about the importance of translating this information into clinical practice. Competing demands, the complexity of HPV vaccine and cervical cancer prevention counseling and diverse community and cultural values will continue to pose challenges to promoting informed decision making for the HPV vaccine in the brief primary care encounter. Given current ACIP recommendations, we focused on the implications of our findings for 11 to 12 year old girls; however, it will be equally important to evaluate these challenges in older adolescents and young adult women in terms of receptivity to the vaccine and feasibility of delivery. 1. Centers for Disease Control. Quadrivalent Human Papillomavirus Vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP). http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5602a1.htm. Accessed: August 2, 2007. 2. Mays RM, Zimet GD, Winston Y, Kee R, Dickes J, Su L. Human papillomavirus, genital warts, Pap smears, and cervical cancer: knowledge and beliefs of adolescent and adult women. Health CareWomen Int. 2000;21(5):361-374. Competing interests: None declared |
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Diane M. Harper, MD, MPH, MS, Hanover, NH, USA Prof., Dartmouth Medical School; Dir., Gynecologic Cancer Prev. Res. Group, Norris Cotton Cancer Ctr
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This excellent paper is an important topic to discuss. A most important issue to discuss is the efforts to be expended by both the public and private health groups to target HPV vaccination. It is inaccurate to state that the HPV vaccines must be given before initiation of sexual activity for two reasons: 1) Epidemiology studies have shown that 85% of HPV infections are related to sexual activity. Likewise, they document that 15% of HPV transmission is not related to sexual activity. Oncogenic anogenital HPV infection occurs in females of all ages, including children, which has not been associated with sexual experience. 2) Vaccine efficacy is not related to prior seropositivity. The 3 year follow-up trials for Gardasil show that women with prior exposure to HPV 16 and 18 (seropositive), but negative DNA at the time of first vaccination enjoyed the same 100% efficacy for 3 years as did the larger cohort of 15-26 year old women both seronegative and PCR negative for HPV 16 and 18 at initial vaccination (1). The concept that women with past HPV 16/18 infections have a lifetime immunity to future HPV 16/18 infections has been discredited with the publication of the NCI Guanacaste, Costa Rica cervical cancer project which showed that women with past HPV 16, 18 or 31 antibodies from natural infection contracted new HPV 16, 18 and 31 infections at the same rate as women with no past HPV 16, 18 or 31 infections (2). The ACIP recommendation is to routinely immunize 11-12 year old girls, but more importantly to include vaccinating the most susceptible women defined as the 'catch up' group through the age of approval, 26 years. Economic modeling indicates that after at least 60 years of vaccine implementation there will be lower rates of cervical cancer if the vaccination process targets only 12 year olds rather than targeting only 18 year olds for all levels of vaccine penetrance in the population (3). Economic modeling also shows, though, that in order to see reductions in cervical cancer rates within 10 years of vaccination, the older women through 26 years must be aggressively targeted for vaccination in addition to the annual 12 year old cohort (3). This suggests that as the vaccine program is initially implemented, targeting women who already understand Pap screening and who have acquaintances with abnormal Paps, may well result in higher uptake and population coverage than targeting only the 12 year old girls. Once successful with vaccinating adult women, once safety of the vaccine in large numbers has been proven, once the duration of the vaccines is established, and once true disease reductions start to occur, the fear of experimenting on young girls will lessen and it may well be far simpler to encourage parents of young girls to vaccinate their children. 1. The FUTURE II Study Group. Quadrivalent vaccine against human papillomavirus to prevent high-grade cervical lesions. N Engl J Med 2007; 356:1915-1927. 2. Viscidi RP, et al. Seroreactivity to Human Papillomavirus (HPV) Types 16, 18, or 31 and Risk of Subsequent HPV Infection: Results from a Population-Based Study in Costa Rica. Cancer Epidemiol Biomarkers Prev 2004; 13:324-327. 3. Elbasha EH, Dasbach EJ, Insinga RP. Model for assessing human papillomavirus vaccination strategies. Emerg Infect Dis. 2007 Jan; 13(1):28-41. Diane M. Harper, MD, MPH, MS, Professor, Dartmouth College, Women's and Gender Studies Program, Hanover, NH Competing interests: Funded for clinical trials for phase II and phase III from Merck for Gardasil development and funded for clinical trials for phase II and phase III from GSK for Cervarix development; and advisory boards for both GSK and Merck. |
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