The Promise of the Human Papillomavirus Vaccine Does Not Confer Immunity Against Ethical Reflection
http://www.100md.com
《肿瘤学家》
ABSTRACT
The recent announcement of an experimental vaccine against human papillomavirus (HPV) has raised great hopes and expectations. Promising trial results, however, should not obscure ethical issues related to a vaccine’s ultimate dissemination. Although lay media might view an HPV vaccine as a panacea, a more complicated ethical reality exists, touching upon public knowledge, health care disparities, and parental consent for childhood vaccination.
INTRODUCTION
The recent announcement of an experimental vaccine against human papillomavirus (HPV) has raised great hopes in the lay press and a recent article in The Oncologist [1–5]. Given the epidemiology and pathogenesis of HPV and HPV-associated diseases, such expectations are understandable. HPV infection is one of the most common sexually transmitted infections worldwide, with approximately 20 million infected men and women in the U.S. [6]. Although most infections are transient, persistent ones can lead to anogenital warts, cervical intraepithelial neoplasia (CIN), and cervical cancer [5, 7].
The promise of a vaccine to reduce the incidence of HPV and its sequelae, however, will be fully realized only if we reflect upon the ethical issues raised by vaccine development and implementation. Among these concerns are the critical need for public education about HPV and its consequences, access to health care resources, health practices that might reinforce problematic stereotypes, and requirements for informed consent.
HPV AND CERVICAL CANCER
Cervical cancer is one of the leading cancers among women. Worldwide, approximately 470,000 cases are diagnosed each year, resulting in approximately 233,000 deaths [8]. Eighty-three percent of these cancers are found in developing countries, with the highest incidence in Latin America, sub-Saharan Africa, and South and Southeast Asia [9]. Each year, genital HPV infection is primarily responsible for about 10,400 new cases of cervical cancer and 3,700 deaths in the U.S. [10]. Beyond cervical cancer morbidity and mortality, hundreds of thousands are also diagnosed with anogenital warts, which are associated with significant psychological burden. HPV has also been linked, in varying degrees, to cancers of the anus, vulva, vagina, and penis [11, 12].
There are two distinct experimental vaccines, one made by Merck & Co., Inc. (Whitehouse Station, NJ) and the other made by GlaxoSmithKline (GSK)(Philadelphia) [13, 14]. Each includes HPV types 16 and 18, which account for about 70% of all cervical cancers worldwide. The Merck vaccine also incorporates HPV types 6 and 11, associated with approximately 90% of genital warts. Reported results indicate that both vaccines might be successful in preventing persistent HPV infection and CIN [13, 14]. Phase III trials are under way for both the quadrivalent and the bivalent vaccines, and Merck has filed for approval with the U.S. Food and Drug Administration. GSK has indicated that it will do the same in Europe and other unspecified countries in 2006 [15].
Ethical Reflection
Promising trial results should not obscure ethical issues related to a vaccine’s ultimate dissemination. Although lay media might view an HPV vaccine as a panacea, a more complicated ethical reality exists, touching upon public knowledge, health care disparities, and parental consent for childhood vaccination.
Hope Without Hype
The portrait of the vaccine in the media as having the ability to "end routine smear tests" exemplifies some of the hype that followed the presentation of the HPV vaccines [4]. This is problematic because it engenders false expectations. Public discussion needs then to be nuanced to ensure that potential recipients appreciate both the benefits and limitations of the vaccine. For example, although both vaccines seem to prevent persistent high-risk HPV infection and the development of CIN, the duration of the antibody protection is unknown. In studies, patients were followed up for 35 months, and there are no available data about antibody protection beyond that time [13]. A second issue is the scope of the vaccination’s reach. The public should be reminded that the two vaccines protect only against two of the high-risk subtypes, which are responsible for just 70% of cancers; thus, there is no protection against the other 30% [5, 15].
The public should also be made aware that in countries with a wide use of Papanicolaou (Pap) smears and HPV screening, the introduction of these new vaccines might contribute little to decreasing cervical cancer rates. Women with access to care will not develop cervical cancer because of early detection of premalignant lesions. In contrast, women in less-screened populations, who might benefit from the vaccination, will paradoxically receive neither the Pap smears nor the vaccine because of a lack of access. Given this, a reduction in cervical cancer rates would only occur if underserved women receive both screening and vaccination [15].
Finally, the vaccines are not therapeutic. Therefore, it is highly unlikely that these vaccines will have much impact on those already infected with HPV or at risk for its malignant sequelae [5]. Again, this population’s disease burden can be mitigated, or down-staged, with comprehensive screening.
Health Care and Fairness
If we consider screening, it is important to appreciate that even this basic public health intervention is marked by health care disparities. While the widespread use of the Pap test in industrialized countries has resulted in a significant decrease in cervical cancer, about 35,000 women die from the disease every year in the U.S. and Europe [8]. Evidence shows that morbidity and mortality for this disease vary according to socioeconomic status, level of education, and ethnicity [16]. Worldwide, women with lower socioeconomic status and less education suffer from a higher incidence of this cancer [17]. Also, the prevalence of screening varies by ethnicity. In the U.S., for example, cervical cancer screening rates are higher than 80% for African-American and non-Hispanic white women, around 78% for Hispanic women, and about 68% for Asian women [18]. Women with health insurance and a usual primary care provider are also more likely to receive screening tests [19].
In developing countries, fewer than 50% of women affected by this disease survive longer than 5 years, while 66% do so in industrialized nations [20]. Because of competing health demands, poorly developed health care systems, wars, lack of information, and poverty, screening programs are difficult to establish in low-resource settings. Furthermore, traditional cytology tests present serious barriers. These programs require highly trained personnel, appropriately equipped laboratories, ongoing staff training, and functional referral systems to communicate with women about results [9]. Given this situation, there is little disagreement about the benefits provided by a safe and effective vaccine against HPV infection in developing countries.
Although the development of immunization holds the most promise for low-income nations, it remains unclear whether these countries will reap these benefits any time soon. It is discouraging if we consider the coverage of other important vaccines and note that worldwide coverage of six key childhood vaccinations is 74% and in some developing countries is as low as 30% [21]. The high cost of the vaccines, lack of political will, and deficient health infrastructure prevent children in resource-poor nations from getting life-saving vaccinations [22].
Vaccines recommended for early adolescents might run into even more problems. Although schools would be a good setting for mass vaccination, many adolescents in developing countries have already ceased going to school. Attendance for girls is even worse [23]. The lack of information about HPV infection and its consequences only contributes to the problem because many parents may believe that the vaccine is unnecessary [21].
International organizations, national governments, research institutions, investigators, and the public should help assure that those most in need have access to HPV vaccines. Appropriate decisions about prioritizing health care resources need to be made, potentially between worthy vaccines for different maladies and other preventive interventions like education or health outreach. Making sure that resources devoted to the introduction of an HPV vaccine do not displace secondary prevention programs is of utmost importance.
HPV and Women
The primary objective of these vaccines is the prevention of cervical cancer, a disease of women. However, casting this infection solely as a woman’s issue may distort funding priorities and increase inappropriate gender stereotypes. These concerns result from the fact that, although some recent trials have included men [24], the testing has primarily involved women. Nonetheless, HPV is a sexually transmitted disease and spread by both men and women. Epidemiological evidence shows that females whose sexual partners have had more sexual contacts have a higher risk for cervical cancer [16]. Cancer risk is also strongly related to the number of a woman’s husband’s extramarital affairs [25]. Further, premature death from cervical cancer affects women at a relatively young age. Consequently, family dynamics are disturbed, as are the lives of husbands, partners, and children. Given these facts, both men and women should share the burden of research and the potential benefits of vaccination.
Moreover, a vaccine for a sexually transmitted disease directed only toward women might reinforce the widespread belief that they ought to take sole responsibility for issues related to reproductive health. Women already bear a disproportionate burden for matters of reproductive decision making [26, 27]. Studies show that men do not perceive themselves to be susceptible to HPV and do not believe HPV infection to be a severe problem for themselves [25]. We must consider then whether these vaccines ought to be tested on men and, if shown to be effective, recommended for them as well. This sort of gender-neutral inclusion can emphasize the need for both men and women to share responsibility equally for sexual and reproductive matters, perhaps having more impact on the sociology of sexually transmitted diseases than vaccines alone.
If HPV vaccination were effective in men, herd immunity suggests that immunizing them would maximize the public health impact of vaccination [28]. Unfortunately, because the vaccines have not been adequately tested in men, it is unclear whether vaccination would have this population-based effect. Until this information is available, it is unclear whether recommendations can be offered to immunize adolescent males.
Consent for Vaccination
If it is determined that adolescents, both male and female, should be vaccinated, public health officials may encounter concerns about parental resistance. After Merck presented its interim phase III results, some questioned whether parents would allow their children to receive the vaccine [29–32]. Because of the high rate of sexual intercourse and number of sexual partners among adolescents—in 2003, 46.7% of high school students had had sexual intercourse—they have been identified as a group at risk [33]. Researchers have thus suggested that girls between the ages of 10 and 13 be vaccinated because they are likely to still be seronegative for HPV [13].
Some have argued that parents’ approval of HPV immunization might be hard to obtain because children would have to be informed about its purpose [29–32]. Some believe this could promote conversations about sexual behavior that parents might be unwilling to have or be uncomfortable discussing [34–36]. Others think that talk about sex could encourage undesirable behavior, with some parents worrying that consent to have the vaccine could be taken as a warrant for early sexual activity [29–32, 34–36].
Despite the valuable nature of such concerns, the data suggest that the number of parents likely to deny consent for their children’s HPV vaccination is small, only about 23% [37]. Although some parents might worry that vaccination could promote risky sexual behavior, the majority of them concede that the benefits provided from the vaccine outweigh such risks [35–37]. Moreover, parents initially opposed to immunization change their minds in favor of allowing vaccination when they are given more information about the virus and its associated ills [38]. Such studies indicate the importance of educational outreach as part of a public health preventive strategy, in tandem with vaccination efforts.
CONCLUSION
Current estimates of the economic burden of HPV infection and its sequelae in the U.S. amount to more than $5 billion per year [11]. To these we must add the emotional and psychological burden of dealing with a sexually transmitted infection and of developing cancer. Doubtless, the advent of safe and effective vaccines against some of the most common high-risk types of HPV infection will certainly be welcome.
Despite such promise, public policymakers need to take into account all the relevant factors in the implementation of these vaccines. Only in this way will they be able to ensure that those most in need have access to these preventive measures and that implementation does not add to injustices already experienced by disadvantaged groups. Investigators have an important role in maintaining the public trust necessary for the successful implementation of vaccination programs like that envisioned for the human papillomavirus.
DISCLOSURE OF POTENTIAL CONFLICTS OF INTEREST
The author indicates no potential conflicts of interest.
REFERENCES
Maugh TH. Vaccine blocks most cancers of the cervix. Los Angeles Times. October 7, 2005.
Grady D. Vaccine prevents most cervical cancer. The New York Times, October 7, 2005.
Howard Price J. Vaccine blocks cancer cause. The Washington Times, October 7, 2005.
Hawkes N. New cancer vaccine will end routine smear tests. The Times, October07,2005.Availableathttp://www.timesonline.co.uk/article/0,,2-1815129,00.html. Accessed January 20, 2006.
Mahdavi A, Monk BJ. Vaccines against human papillomavirus and cervical cancer: promises and challenges. The Oncologist 2005;10:528–538.
Cates W Jr. Estimates of the incidence and prevalence of sexually transmitted diseases in the United States. American Social Health Association Panel. Sex Transm Dis 1999;26(4 suppl):S2–S7.
Bosch FX, Lorincz A, Munoz N et al. The causal relation between human papillomavirus and cervical cancer. J Clin Pathol 2002;55:244–265.
Parkin DM, Bray F, Ferlay J et al. Estimating the world cancer burden: Globocan 2000. Int J Cancer 2001;94:153–156.
Denny L. The prevention of cervical cancer in developing countries. BJOG 2005;112:1204–1212.
Jemal A, Murray T, Ward E et al. Cancer statistics, 2005. CA Cancer J Clin 2005;55:10–30.
Insinga RP, Dasbach EJ, Elbasha EH. Assessing the annual economic burden of preventing and treating anogenital human papillomavirus-related disease in the US: analytic framework and review of the literature. Pharmacoeconomics 2005;23:1107–1122.
Kahn JA. Vaccination as a prevention strategy for human papillomavirus-related diseases. J Adolesc Health 2005;37(6 suppl):S10–S16.
Villa LL, Costa RL, Petta CA et al. Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in young women: a randomised double-blind placebo-controlled multicentre phase II efficacy trial. Lancet Oncol 2005;6:271–278.
Harper DM, Franco EL, Wheeler C et al. Efficacy of a bivalent L1 virus-like particle vaccine in prevention of infection with human papillomavirus types 16 and 18 in young women: a randomized controlled trial. Lancet 2004;364:1757–1765.
Cohen J. Public health. High hopes and dilemmas for a cervical cancer vaccine. Science 2005;308:618–621.
Newmann SJ, Garner EO. Social inequities along the cervical cancer continuum: a structured review. Cancer Causes Control 2005;16:63–70.
de Sanjose S, Bosch FX, Munoz N et al. Social differences in sexual behaviour and cervical cancer. IARC Sci Publ 1997;138:309–317.
American Cancer Society. Cancer Prevention and Early Detection Facts and Figures 2005. Atlanta: American Cancer Society, 2005:1–60.
Loerzel VW, Bushy A. Interventions that address cancer health disparities in women. Fam Community Health 2005;28:79–89.
Franco EL, Harper DM. Vaccination against human papillomavirus infection: a new paradigm in cervical cancer control. Vaccine 2005;23: 2388–2394.
Jacob M, Bradley J, Barone MA. Human papillomavirus vaccines: what does the future hold for preventing cervical cancer in resource-poor settings through immunization programs? Sex Transm Dis 2005;32: 635–640.
Baleta A. African conference highlights gaps in vaccination. Lancet Infect Dis 2005;5:472–473.
The United Nations Children’s Fund (UNICEF). The State of the World’s Children 2004. New York: UNICEF, 2003:1–148.
Geipert N. Vaccinating men for HPV: new strategy for preventing cervical cancer in women? J Natl Cancer Inst 2005;97:630–631.
McPartland TS, Weaver BA, Lee SK et al. Men’s perceptions and knowledge of human papillomavirus (HPV) infection and cervical cancer. J Am Coll Health 2005;53:225–230.
Holmes H, Hoskins B, Gross M, eds. Birth Control and Controlling Birth: Women-Centered Perspectives. Clifton, NJ: Humana Press, 1980:1–338.
Nelson HL, Nelson JL. Feminism, social policy, and long-acting contraception. Hastings Cent Rep 1995;25:S30–S32.
Garnett GP. Role of herd immunity in determining the effect of vaccines against sexually transmitted disease. J Infect Dis 2005;191(suppl 1): S97–S106.
Goodenough P. Vaccine for Cancer-Causing Virus Could Spark Controversy. CNSNews.com. April 28, 2005.
Gujon J. Cancer and the culture wars. The coming storm over a cancer vaccine. Fortune, October 31, 2005.
Washam C. Targeting teens and adolescents for HPV vaccine could draw fire. J Natl Cancer Inst 2005;97:1030–1031.
Stein R. Cervical cancer vaccine gets injected with a social issue. Washington Post, October 31, 2005:A03.
Centers for Disease Control and Prevention (CDC). Youth Risk Behavior Surveillance—United States, 2003. Surveillance Summaries, May 21, 2004. MMWR 2004;53(No. SS-2).
Zimet GD. Improving adolescent health: focus on HPV vaccine acceptance. J Adolesc Health 2005;37(6 suppl):S17–S23.
Zimet GD, Mays RM, Sturm LA et al. Parental attitudes about sexually transmitted infection vaccination for their adolescent children. Arch Pediatr Adolesc Med 2005;159:132–137.
Mays RM, Sturm LA, Zimet GD. Parental perspectives on vaccinating children against sexually transmitted infections. Soc Sci Med 2004;58:1405–1413.
Liddon N, Pulley L, Cockerham WC et al. Parents’/guardians’ willingness to vaccinate their children against genital herpes. J Adolesc Health 2005;37:187–193.
Davis K, Dickman ED, Ferris D et al. Human papillomavirus vaccine acceptability among parents of 10- to 15-year-old adolescents. J Low Genit Tract Dis 2004;8:188–194.(Inmaculada de Melo-Martín)
The recent announcement of an experimental vaccine against human papillomavirus (HPV) has raised great hopes and expectations. Promising trial results, however, should not obscure ethical issues related to a vaccine’s ultimate dissemination. Although lay media might view an HPV vaccine as a panacea, a more complicated ethical reality exists, touching upon public knowledge, health care disparities, and parental consent for childhood vaccination.
INTRODUCTION
The recent announcement of an experimental vaccine against human papillomavirus (HPV) has raised great hopes in the lay press and a recent article in The Oncologist [1–5]. Given the epidemiology and pathogenesis of HPV and HPV-associated diseases, such expectations are understandable. HPV infection is one of the most common sexually transmitted infections worldwide, with approximately 20 million infected men and women in the U.S. [6]. Although most infections are transient, persistent ones can lead to anogenital warts, cervical intraepithelial neoplasia (CIN), and cervical cancer [5, 7].
The promise of a vaccine to reduce the incidence of HPV and its sequelae, however, will be fully realized only if we reflect upon the ethical issues raised by vaccine development and implementation. Among these concerns are the critical need for public education about HPV and its consequences, access to health care resources, health practices that might reinforce problematic stereotypes, and requirements for informed consent.
HPV AND CERVICAL CANCER
Cervical cancer is one of the leading cancers among women. Worldwide, approximately 470,000 cases are diagnosed each year, resulting in approximately 233,000 deaths [8]. Eighty-three percent of these cancers are found in developing countries, with the highest incidence in Latin America, sub-Saharan Africa, and South and Southeast Asia [9]. Each year, genital HPV infection is primarily responsible for about 10,400 new cases of cervical cancer and 3,700 deaths in the U.S. [10]. Beyond cervical cancer morbidity and mortality, hundreds of thousands are also diagnosed with anogenital warts, which are associated with significant psychological burden. HPV has also been linked, in varying degrees, to cancers of the anus, vulva, vagina, and penis [11, 12].
There are two distinct experimental vaccines, one made by Merck & Co., Inc. (Whitehouse Station, NJ) and the other made by GlaxoSmithKline (GSK)(Philadelphia) [13, 14]. Each includes HPV types 16 and 18, which account for about 70% of all cervical cancers worldwide. The Merck vaccine also incorporates HPV types 6 and 11, associated with approximately 90% of genital warts. Reported results indicate that both vaccines might be successful in preventing persistent HPV infection and CIN [13, 14]. Phase III trials are under way for both the quadrivalent and the bivalent vaccines, and Merck has filed for approval with the U.S. Food and Drug Administration. GSK has indicated that it will do the same in Europe and other unspecified countries in 2006 [15].
Ethical Reflection
Promising trial results should not obscure ethical issues related to a vaccine’s ultimate dissemination. Although lay media might view an HPV vaccine as a panacea, a more complicated ethical reality exists, touching upon public knowledge, health care disparities, and parental consent for childhood vaccination.
Hope Without Hype
The portrait of the vaccine in the media as having the ability to "end routine smear tests" exemplifies some of the hype that followed the presentation of the HPV vaccines [4]. This is problematic because it engenders false expectations. Public discussion needs then to be nuanced to ensure that potential recipients appreciate both the benefits and limitations of the vaccine. For example, although both vaccines seem to prevent persistent high-risk HPV infection and the development of CIN, the duration of the antibody protection is unknown. In studies, patients were followed up for 35 months, and there are no available data about antibody protection beyond that time [13]. A second issue is the scope of the vaccination’s reach. The public should be reminded that the two vaccines protect only against two of the high-risk subtypes, which are responsible for just 70% of cancers; thus, there is no protection against the other 30% [5, 15].
The public should also be made aware that in countries with a wide use of Papanicolaou (Pap) smears and HPV screening, the introduction of these new vaccines might contribute little to decreasing cervical cancer rates. Women with access to care will not develop cervical cancer because of early detection of premalignant lesions. In contrast, women in less-screened populations, who might benefit from the vaccination, will paradoxically receive neither the Pap smears nor the vaccine because of a lack of access. Given this, a reduction in cervical cancer rates would only occur if underserved women receive both screening and vaccination [15].
Finally, the vaccines are not therapeutic. Therefore, it is highly unlikely that these vaccines will have much impact on those already infected with HPV or at risk for its malignant sequelae [5]. Again, this population’s disease burden can be mitigated, or down-staged, with comprehensive screening.
Health Care and Fairness
If we consider screening, it is important to appreciate that even this basic public health intervention is marked by health care disparities. While the widespread use of the Pap test in industrialized countries has resulted in a significant decrease in cervical cancer, about 35,000 women die from the disease every year in the U.S. and Europe [8]. Evidence shows that morbidity and mortality for this disease vary according to socioeconomic status, level of education, and ethnicity [16]. Worldwide, women with lower socioeconomic status and less education suffer from a higher incidence of this cancer [17]. Also, the prevalence of screening varies by ethnicity. In the U.S., for example, cervical cancer screening rates are higher than 80% for African-American and non-Hispanic white women, around 78% for Hispanic women, and about 68% for Asian women [18]. Women with health insurance and a usual primary care provider are also more likely to receive screening tests [19].
In developing countries, fewer than 50% of women affected by this disease survive longer than 5 years, while 66% do so in industrialized nations [20]. Because of competing health demands, poorly developed health care systems, wars, lack of information, and poverty, screening programs are difficult to establish in low-resource settings. Furthermore, traditional cytology tests present serious barriers. These programs require highly trained personnel, appropriately equipped laboratories, ongoing staff training, and functional referral systems to communicate with women about results [9]. Given this situation, there is little disagreement about the benefits provided by a safe and effective vaccine against HPV infection in developing countries.
Although the development of immunization holds the most promise for low-income nations, it remains unclear whether these countries will reap these benefits any time soon. It is discouraging if we consider the coverage of other important vaccines and note that worldwide coverage of six key childhood vaccinations is 74% and in some developing countries is as low as 30% [21]. The high cost of the vaccines, lack of political will, and deficient health infrastructure prevent children in resource-poor nations from getting life-saving vaccinations [22].
Vaccines recommended for early adolescents might run into even more problems. Although schools would be a good setting for mass vaccination, many adolescents in developing countries have already ceased going to school. Attendance for girls is even worse [23]. The lack of information about HPV infection and its consequences only contributes to the problem because many parents may believe that the vaccine is unnecessary [21].
International organizations, national governments, research institutions, investigators, and the public should help assure that those most in need have access to HPV vaccines. Appropriate decisions about prioritizing health care resources need to be made, potentially between worthy vaccines for different maladies and other preventive interventions like education or health outreach. Making sure that resources devoted to the introduction of an HPV vaccine do not displace secondary prevention programs is of utmost importance.
HPV and Women
The primary objective of these vaccines is the prevention of cervical cancer, a disease of women. However, casting this infection solely as a woman’s issue may distort funding priorities and increase inappropriate gender stereotypes. These concerns result from the fact that, although some recent trials have included men [24], the testing has primarily involved women. Nonetheless, HPV is a sexually transmitted disease and spread by both men and women. Epidemiological evidence shows that females whose sexual partners have had more sexual contacts have a higher risk for cervical cancer [16]. Cancer risk is also strongly related to the number of a woman’s husband’s extramarital affairs [25]. Further, premature death from cervical cancer affects women at a relatively young age. Consequently, family dynamics are disturbed, as are the lives of husbands, partners, and children. Given these facts, both men and women should share the burden of research and the potential benefits of vaccination.
Moreover, a vaccine for a sexually transmitted disease directed only toward women might reinforce the widespread belief that they ought to take sole responsibility for issues related to reproductive health. Women already bear a disproportionate burden for matters of reproductive decision making [26, 27]. Studies show that men do not perceive themselves to be susceptible to HPV and do not believe HPV infection to be a severe problem for themselves [25]. We must consider then whether these vaccines ought to be tested on men and, if shown to be effective, recommended for them as well. This sort of gender-neutral inclusion can emphasize the need for both men and women to share responsibility equally for sexual and reproductive matters, perhaps having more impact on the sociology of sexually transmitted diseases than vaccines alone.
If HPV vaccination were effective in men, herd immunity suggests that immunizing them would maximize the public health impact of vaccination [28]. Unfortunately, because the vaccines have not been adequately tested in men, it is unclear whether vaccination would have this population-based effect. Until this information is available, it is unclear whether recommendations can be offered to immunize adolescent males.
Consent for Vaccination
If it is determined that adolescents, both male and female, should be vaccinated, public health officials may encounter concerns about parental resistance. After Merck presented its interim phase III results, some questioned whether parents would allow their children to receive the vaccine [29–32]. Because of the high rate of sexual intercourse and number of sexual partners among adolescents—in 2003, 46.7% of high school students had had sexual intercourse—they have been identified as a group at risk [33]. Researchers have thus suggested that girls between the ages of 10 and 13 be vaccinated because they are likely to still be seronegative for HPV [13].
Some have argued that parents’ approval of HPV immunization might be hard to obtain because children would have to be informed about its purpose [29–32]. Some believe this could promote conversations about sexual behavior that parents might be unwilling to have or be uncomfortable discussing [34–36]. Others think that talk about sex could encourage undesirable behavior, with some parents worrying that consent to have the vaccine could be taken as a warrant for early sexual activity [29–32, 34–36].
Despite the valuable nature of such concerns, the data suggest that the number of parents likely to deny consent for their children’s HPV vaccination is small, only about 23% [37]. Although some parents might worry that vaccination could promote risky sexual behavior, the majority of them concede that the benefits provided from the vaccine outweigh such risks [35–37]. Moreover, parents initially opposed to immunization change their minds in favor of allowing vaccination when they are given more information about the virus and its associated ills [38]. Such studies indicate the importance of educational outreach as part of a public health preventive strategy, in tandem with vaccination efforts.
CONCLUSION
Current estimates of the economic burden of HPV infection and its sequelae in the U.S. amount to more than $5 billion per year [11]. To these we must add the emotional and psychological burden of dealing with a sexually transmitted infection and of developing cancer. Doubtless, the advent of safe and effective vaccines against some of the most common high-risk types of HPV infection will certainly be welcome.
Despite such promise, public policymakers need to take into account all the relevant factors in the implementation of these vaccines. Only in this way will they be able to ensure that those most in need have access to these preventive measures and that implementation does not add to injustices already experienced by disadvantaged groups. Investigators have an important role in maintaining the public trust necessary for the successful implementation of vaccination programs like that envisioned for the human papillomavirus.
DISCLOSURE OF POTENTIAL CONFLICTS OF INTEREST
The author indicates no potential conflicts of interest.
REFERENCES
Maugh TH. Vaccine blocks most cancers of the cervix. Los Angeles Times. October 7, 2005.
Grady D. Vaccine prevents most cervical cancer. The New York Times, October 7, 2005.
Howard Price J. Vaccine blocks cancer cause. The Washington Times, October 7, 2005.
Hawkes N. New cancer vaccine will end routine smear tests. The Times, October07,2005.Availableathttp://www.timesonline.co.uk/article/0,,2-1815129,00.html. Accessed January 20, 2006.
Mahdavi A, Monk BJ. Vaccines against human papillomavirus and cervical cancer: promises and challenges. The Oncologist 2005;10:528–538.
Cates W Jr. Estimates of the incidence and prevalence of sexually transmitted diseases in the United States. American Social Health Association Panel. Sex Transm Dis 1999;26(4 suppl):S2–S7.
Bosch FX, Lorincz A, Munoz N et al. The causal relation between human papillomavirus and cervical cancer. J Clin Pathol 2002;55:244–265.
Parkin DM, Bray F, Ferlay J et al. Estimating the world cancer burden: Globocan 2000. Int J Cancer 2001;94:153–156.
Denny L. The prevention of cervical cancer in developing countries. BJOG 2005;112:1204–1212.
Jemal A, Murray T, Ward E et al. Cancer statistics, 2005. CA Cancer J Clin 2005;55:10–30.
Insinga RP, Dasbach EJ, Elbasha EH. Assessing the annual economic burden of preventing and treating anogenital human papillomavirus-related disease in the US: analytic framework and review of the literature. Pharmacoeconomics 2005;23:1107–1122.
Kahn JA. Vaccination as a prevention strategy for human papillomavirus-related diseases. J Adolesc Health 2005;37(6 suppl):S10–S16.
Villa LL, Costa RL, Petta CA et al. Prophylactic quadrivalent human papillomavirus (types 6, 11, 16, and 18) L1 virus-like particle vaccine in young women: a randomised double-blind placebo-controlled multicentre phase II efficacy trial. Lancet Oncol 2005;6:271–278.
Harper DM, Franco EL, Wheeler C et al. Efficacy of a bivalent L1 virus-like particle vaccine in prevention of infection with human papillomavirus types 16 and 18 in young women: a randomized controlled trial. Lancet 2004;364:1757–1765.
Cohen J. Public health. High hopes and dilemmas for a cervical cancer vaccine. Science 2005;308:618–621.
Newmann SJ, Garner EO. Social inequities along the cervical cancer continuum: a structured review. Cancer Causes Control 2005;16:63–70.
de Sanjose S, Bosch FX, Munoz N et al. Social differences in sexual behaviour and cervical cancer. IARC Sci Publ 1997;138:309–317.
American Cancer Society. Cancer Prevention and Early Detection Facts and Figures 2005. Atlanta: American Cancer Society, 2005:1–60.
Loerzel VW, Bushy A. Interventions that address cancer health disparities in women. Fam Community Health 2005;28:79–89.
Franco EL, Harper DM. Vaccination against human papillomavirus infection: a new paradigm in cervical cancer control. Vaccine 2005;23: 2388–2394.
Jacob M, Bradley J, Barone MA. Human papillomavirus vaccines: what does the future hold for preventing cervical cancer in resource-poor settings through immunization programs? Sex Transm Dis 2005;32: 635–640.
Baleta A. African conference highlights gaps in vaccination. Lancet Infect Dis 2005;5:472–473.
The United Nations Children’s Fund (UNICEF). The State of the World’s Children 2004. New York: UNICEF, 2003:1–148.
Geipert N. Vaccinating men for HPV: new strategy for preventing cervical cancer in women? J Natl Cancer Inst 2005;97:630–631.
McPartland TS, Weaver BA, Lee SK et al. Men’s perceptions and knowledge of human papillomavirus (HPV) infection and cervical cancer. J Am Coll Health 2005;53:225–230.
Holmes H, Hoskins B, Gross M, eds. Birth Control and Controlling Birth: Women-Centered Perspectives. Clifton, NJ: Humana Press, 1980:1–338.
Nelson HL, Nelson JL. Feminism, social policy, and long-acting contraception. Hastings Cent Rep 1995;25:S30–S32.
Garnett GP. Role of herd immunity in determining the effect of vaccines against sexually transmitted disease. J Infect Dis 2005;191(suppl 1): S97–S106.
Goodenough P. Vaccine for Cancer-Causing Virus Could Spark Controversy. CNSNews.com. April 28, 2005.
Gujon J. Cancer and the culture wars. The coming storm over a cancer vaccine. Fortune, October 31, 2005.
Washam C. Targeting teens and adolescents for HPV vaccine could draw fire. J Natl Cancer Inst 2005;97:1030–1031.
Stein R. Cervical cancer vaccine gets injected with a social issue. Washington Post, October 31, 2005:A03.
Centers for Disease Control and Prevention (CDC). Youth Risk Behavior Surveillance—United States, 2003. Surveillance Summaries, May 21, 2004. MMWR 2004;53(No. SS-2).
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