Note: NNii does not advocate for immunization policies: our task is to provide information. Because many states are considering whether or not to mandate HPV vaccine for school entry to prevent cervical cancer and because the scientific community and ethicists are also debating this issue, we wrote this essay to outline the issues pro and con HPV vaccine mandates.
The recommendation that all 11-12 year old girls (as well as women up to 26 years of age) be immunized with HPV vaccine was an important public health milestone. However, mandating this vaccine for school attendance raises a number of unique social, ethical and moral questions. Before addressing these questions, let’s consider some issues about HPV infections and vaccines as well as about immunization mandates for school attendance.
1. Infection with HPV types that cause cancer. While some HPV types are spread by casual contact, other types are acquired by intimate sexual contact. These are known as genital HPV infections. Genital HPVs cause cervical cancer—as well as other cancers and genital warts.
- By 50 years of age, 70-80% of women will have acquired genital HPV infection—often with more than one type of HPV.
- Adolescents and young adults are very likely to acquire genital HPV infection within a few months after beginning sexual activity.
- A woman can also be infected with HPV by involuntary sexual exposure—such as date rape—as well as by her husband (or partner) if he was infected from a prior sexual partner, even if she were abstinent until marriage.
- Although the vast majority of women recover uneventfully from high-risk (cancer causing) genital HPV infections, some of these infections may lead to persistent infection, cause abnormal Pap tests, and progress to cervical cancer. Regular Pap screening and then the treatment of any abnormalities that are detected prevent many HPV infections from causing cervical cancer.
2. Vaccines against HPV. Two HPV vaccines have been under development in the United States and one of these was licensed in June 2006.
The new vaccines target HPV types 16 and 18, which cause about 70% of the cases of cervical cancer. However:
- The vaccines do not protect a woman who is infected withe vaccine strain of HPV infection before she is vaccinated—that is, vaccine needs to be administered prior to exposure to the virus.
- They do not protect against other high risk (cancer causing) strains not in the vaccine—therefore, they will not eliminate all HPV-caused cancers. Thus, screening and treatment programs will still be needed to reduce cervical cancer deaths.
Because these vaccines prevent persistent genital HPV infections, they also may have the potential to reduce the transmission of these particular strains from person to person.
The vaccines appear to be very safe. Nevertheless, unexpected rare adverse events may not be detected until after many more people have been immunized.
3. Vaccine recommendations and school mandates. The individual states determine which vaccines should be required for school and daycare entry based on the public health needs of the state, usually based upon the Centers for Disease Control and Prevention (CDC) recommendations. States require that school children be immunized against certain diseases to protect bothe the vaccine recipient and his/her schoolmates from contagious illnesses. State requirements differ.
- School mandates have increased immunization levels and have reduced disease outbreaks, including among those who cannot receive the vaccine because of medical reasons.
- Most states permit religious and/or philosophical exemptions, in addition to exemptions for medical contraindications.
- Children who have been exempted from compulsory immunization for religious or philosophical reasons are many times more likely to both acquire and spread vaccine-preventable diseases.
4. Universal HPV immunization of school girls. The CDC has made a universal recommendation for girls 11-12 years of age to receive the HPV vaccine (as well as older girls and women):
- A universal recommendation helps remove the social stigma associated with receiving the HPV vaccine; that is, girls or women who receive the vaccine should not be considered to be “more likely to engage in risky sexual behavior” than their peers.
- A universal recommendation makes the vaccine eligible for funding through the Vaccines For Children (VFC) program. In addition, any serious adverse events associated with the vaccine can be addressed under the Vaccine Injury Compensation Program.
Prevention of genital HPV infections
Avoiding HPV exposure. HPV infections are usually without symptoms and can last for decades. For that reason, it is not possible to accurately assess the risk of acquiring a genital HPV infection from any specific sexual partner.
- Total sexual abstinence is logically the best protection against acquiring all sexually transmitted infections, including genital HPVs. However, it will not protect a woman against involuntary exposure such as date rape and is not a very practical long term strategy.
- Abstinence until marriage does not protect a woman if her husband is infected from a prior sexual partner.
- Monogamy by both sexual partners could possibly assure a woman’s protection—but only if both partners have been abstinent and they remain strictly monogamous.
Limiting HPV exposures. Sexual behaviors are the most important risk factors for acquiring genital HPV infection. Delaying sexual intercourse and limiting the number of sexual partners could reduce the risk of HPV infection. But:
- More than 7% of high school students have their first sexual intercourse before 13 years of age and 62% of girls and 70% of boys have had sexual intercourse by the end of 12th grade. By ninth grade, almost 11% have had more than four sex partners.
- Consistent condom use may or may not provide some protection against acquiring HPV—but condoms do protect against other sexually transmitted infections, some of which may relate to whether her HPV infection progresses to cervical cancer or not.
Preventive HPV Vaccines. The most effective strategy to prevent HPV infection with the strains in the vaccine (which cause 70% of the cases of cervical cancer) is to immunize women before they become infected. That is why immunization is recommended for all girls at 11-12 years of age. However:
- The current HPV vaccines will not protect against other strains of HPV. Thirty percent of cervical cancers are due to infection with strains not included in the vaccine.
- It is not yet known how long vaccine-induced immunity will last.
Compulsory HPV immunization. Mandating HPV immunization for school entry would increase the proportion of girls and women who are immunized—and therefore immune to the HPV types in the vaccine—before most of them will be exposed. This is the most compelling argument in favor of mandating this vaccine.
Others argue that HPV mandates are not appropriate because school immunization laws are intended to control outbreaks of contagious diseases—such as measles, diphtheria and others—that can spread easily to other school children in the classroom. HPV is spread only by intimate sexual contact.
Other factors to consider are:
- Costs of the vaccine. The vaccine is expensive (about $120 per dose for the three shot series). To be most effective, a girl needs to receive the entire 3 dose series, which requires three healthcare visits (two more than is usual). The VFC and some health insurance plans cover the costs of the 3 HPV vaccine doses and clinic visits. But not all families have insurance, not all insurance plans cover HPV vaccine, and most children are not VFC eligible.
- Possible vaccine-associated disparities. Poorer women are more likely to develop HPV infection and develop cervical cancer. If poor women can not afford to get the vaccine, this disparity could become greater. However, compulsory HPV vaccination could reduce the disease burden disparity by assuring all socioeconomic groups of women obtain the vaccine. Whether HPV immunization is compulsory or not, the cost of the vaccine will keep some girls and women from receiving the vaccine.
- Exemptions to compulsory immunization. Many parents and young women who feel that laws requiring HPV immunization would conflict with their beliefs and their personal liberties—or cost too much—would have a means of opting out of compulsory HPV immunization. A possible, unintended, adverse consequence then could be that people who opt out of HPV vaccine might also opt out of other vaccines intended for this age group.
Could other mandates provide insight?
- Hepatitis B (HBV), like HPV, is largely a sexually transmitted infection that can lead to liver cancer. HBV vaccine is recommended at birth and most states require HBV immunization for day care and school entry. However, mandates for HBV vaccine are different, because as many as 30% of HBV infections have no known sexual contacts (or other high risk behaviors).
- Tetanus is a serious, life threatening illness that is not spread from person to person but which is, nevertheless, required for school and day care attendance. However, all diphtheria and pertussis vaccines include tetanus as a component.
- Bicycle helmets and infant car seats are compulsory for children in some communities.
Parental acceptance of HPV vaccines for their 11-12 year old daughters will affect whether the vaccine is widely used in this age group. Most (75%) parents in a recent California study indicated that they would likely give their daughters the HPV vaccine before the age of 13 years in order to keep their daughters safe. However, 25% of parents have reservations about having their daughters immunized at that age. The reasons they gave were their concern that vaccination might influence their daughter’s sexual behaviors, their uneasiness about the morality of immunizing to prevent sexually transmitted infections, and worries about the safety of the vaccine.
- Will girls and women who receive the HPV vaccine be more likely to engage in risky behavior? Preventing other sexually transmitted infections such as HIV (the cause of AIDS), gonorrhea, genital herpes etc. through abstinence and safe sex practices remains important for girls to understand. It seems unlikely that a vaccine that prevents a small number sexually transmitted infections which have no symptoms would cause girls to be promiscuous or have unsafe sex, as some have suggested. However, there is no evidence to support or refute this concern.
- Potential adverse events from the HPV vaccine. Since our experience with this new vaccine is limited and not all women are exposed to high risk HPVs, some girls could experience rare vaccine adverse events not yet identified without a corresponding benefit.
Will immunized women stop seeking cervical cancer screening programs?
Some have speculated that HPV-immunized women might not participate in cervical cancer screening programs, thinking that they are not at risk anymore. The truth is that they remain at risk for other high risk HPV infections and any pre-existing HPV infection that they may have acquired prior to HPV immunization. There is no evidence to support or refute this concern either.
Will universal HPV immunization reduce transmission of vaccine-strain HPVs?
Although universal HPV vaccination may well reduce the transmission of the vaccine type strains, there is no data that addresses this issue. However, it seems unlikely that universal immunization of girls and young women would reduce transmission, in the absence of an intervention to prevent transmission by and to men. Data concerning the safety and effectiveness of the vaccine for boys and men is being collected but is not available yet.
Colgrove J. (2006). The ethics and politics of compulsory HPV vaccination. N Engl J Med 355; 2389-91.
Zimmerman RK. (2006). Ethical analysis of HPV vaccine policy options. Vaccine 24; 4812-20.
Constantine NA, Jerman P. (2007). Acceptance of human Papillomavirus vaccination among Californian parents of daughters: a representative statewide analysis. J Adol Health 40; 108-15.