Not long ago, the public embraced vaccination as nothing short of a medical miracle. Children lined up outside clinics with smiles and sleeves rolled up, eager to receive a lollipop, a Polio Pioneer button and a shot. None of them knew if the shot contained the vaccine or placebo, but they considered themselves lucky for the chance to participate in history. The polio vaccine, along with other vaccines before and after it, constitutes one of the most important public health initiatives ever invented.
Table 1: Misconceptions
www.cdc.gov/nip/publications/6mishome.htm |
Today, physicians find themselves challenged by parents to explain why vaccines are necessary, and they are called to defend the safety record of vaccines in the face of proliferating misinformation and anti-vaccine rhetoric. On September 18, 2002, an interactive symposium was held in Chicago entitled “An Ounce of Prevention: Communicating the Benefits and Risks of Vaccines to Parents.” Sixty-five pediatricians from a variety of practice settings were convened with a distinguished faculty to develop a framework for communication with parents that informs, answers questions, empowers parents with scientific facts and preserves the successes of immunization programs.
One could ask the simple question: “What has changed since the days of Albert Sabin, MD, and Jonas Salk, MD?” The answer is that diseases have disappeared and fear of disease has been replaced by fear of vaccines. It is necessary to continue to reevaluate the risk/benefit formula regarding vaccines. For example, the risk of vaccine-associated paralytic polio (VAPP) caused by oral polio vaccine (OPV), estimated to occur once for every 2.4 million doses distributed, was acceptable at a time when 20,000 devastating cases of natural polio occurred each year in the United States.
However, with no cases of natural polio in the country since 1979 and no cases in the Western Hemisphere since 1991, the risk of five or 10 cases of VAPP each year outweighed the benefits of OPV. This is what prompted the switch to the inactivated polio vaccine (IPV) in 2000.2
The history of the polio vaccine illustrates that, in policy-making, risks and benefits are carefully weighed. However, in recent years, some parents have become convinced that vaccine policies ignore the “facts” about vaccines, many of which are actually misconceptions perpetuated on the Internet and in the lay press.3 Some of these misconceptions are addressed by the Centers for Disease Control and Prevention in a paper entitled “Six common misconceptions about vaccination and how to respond to them” (Table 1).
The truths about vaccines are also worth reviewing. First, that vaccines have been an important public health achievement, has already been alluded to (Table 2). The second truth is that public concern about vaccines is pervasive. Articles in magazines, segments on television talk shows, sound bytes on the evening news, hearings on Capitol Hill and conversations at dinner parties all attest to this. The third truth, that fear of vaccines can lead directly to public harm, may not be so obvious. In the United Kingdom and other countries in the 1970s, fear that whole-cell pertussis vaccine caused encephalopathy led to dramatic declines in vaccine uptake and consequent epidemics of disease.4 Senseless deaths occurred because children were not vaccinated. While whole-cell pertussis vaccine was reactogenic, there remains no proof that it caused permanent neurological damage.
This leads to the fourth truth that vaccines are not 100% safe. However, the safety net in place to detect serious adverse effects from vaccines is extensive, beginning with controlled clinical trials and rigorous licensing procedures and continuing with post-marketing surveillance, the Vaccine Adverse Event Reporting System and ongoing review by bodies like the Institute of Medicine.
Table 2: Vaccine Truths
- Vaccines are one of the most important public health achievements
- Public concern about vaccines is pervasive
- Fear of vaccines can lead to public harm
- Vaccines are not 100% safe
- Parents want what is best for their children
- The public has little understanding of the vaccine development process
- Risk perception is critical
- There are anti-vaccine champions
- Questions remain
- The decision not to vaccinate is an active decision to accept the risks of disease
(Courtesy of Gary S. Marshall, MD.)
The experience with the rotavirus (Rotashield, Wyeth) vaccine illustrates the effectiveness of this safety net.5,6 Within one year of licensure, intussusception associated with the vaccine was detected and vaccine use was suspended. The attributable risk is now estimated to be less than one case per every 10,000 vaccinations, which is actually lower than the natural incidence of intussusception (around one in 2,000 infants); this level of risk was too low to have been detected in prelicensure trials, in which approximately 11,000 children received the vaccine. Ongoing clinical trials of new rotavirus vaccines will enroll tens of thousands of children to ensure that those vaccines do not cause intussusception.
The fifth truth is that parents want what is best for their children. The problem is not that they want harm to come to their children but rather that many have become convinced that responsible parenting means protecting their children from the vaccines rather than the diseases. Physicians must reframe the discussion about vaccines so parents understand the risks of the diseases and the risks of the vaccines in the proper context.
The sixth truth is that parents have little understanding of vaccinology. The effort involved in isolating the causative agent, understanding disease pathogenesis, determining correlates of protection, testing vaccine prototypes in animals, establishing safety, conducting field trials and collecting a database that allows for licensure is underappreciated. This process takes many years of research as well as millions of dollars of funding.
The seventh truth about vaccines is that risk perception is critical. Without minimizing the importance of preparedness for bioterrorism, it is ironic to point out that, most likely, no one will die of smallpox in the United States this year, but approximately 20,000 people will die of influenza. Yet, parents who are leery of influenza vaccination express interest in smallpox vaccine because of the perception of risk. Parents living in non-endemic areas expressed interest in the Lyme vaccine because the disease was perceived to be serious; at the same time, many parents took their children to chickenpox parties because they perceived acquiring the natural disease to be less risky than the varicella vaccine. In the early 1990s, there were approximately 50 pediatric deaths each year from varicella,7 which were more deaths than from any other disease preventable by a routinely administered childhood vaccine at the time.
The eighth truth is that just as there are vaccine champions, there are vaccine anti-champions. No one can argue that the attention brought to vaccine safety issues by activists has not benefited the public. Much of the expansion of the vaccine safety net can be attributed to this activity. However, much of the information that is easily accessible to parents (e.g. on the Internet8) is not accurate. The only available filter through which parents can interpret this information is the primary-care physician. Studies have repeatedly shown that, in addition to laying out the facts, the personal endorsement of the physician is the most important aspect of advocating for vaccines in practice.
The ninth truth is that many questions about vaccines remain. For example, which vaccine safety claims are worth investigating? Clearly, not every claim can be studied, and perhaps only those with reasonably plausible hypotheses deserve scientific attention. How can the medical community and the vaccine industry address issues of conflict of interest while advocating for vaccination? What financial and logistical barriers do practitioners face in promoting vaccination? How do families differ in their orientation toward traditional medicine, and how should the physician’s approach to discussing vaccine safety with parents be adjusted based on that orientation?
Parents may think that in accepting vaccinations they are making active choices and that in refusing vaccinations they are passively deferring to the status quo. In fact, the (tenth) truth is that the decision to refuse vaccination is an active decision to accept the risks of the disease. This idea may help some parents place the true risks and benefits of vaccination in perspective and make informed decisions.
- CDC. Achievements in public health, 1990-1999: Impact of vaccines universally recommended for children — United States, 1990-1998. MMWR.1999;48:243-248.
- CDC. Poliomyelitis prevention in the United States: Updated recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2000;49(RR-5):1-22.
- Poland GA, Jacobson RM. Understanding those who do not understand: A brief review of the antivaccine movement. Vaccine. 2001;19: 2440-2445.
- Gangarosa EJ, Galazka AM, Wolfe CR, et al. Impact of anti-vaccine movements on pertussis control: The untold story. Lancet. 1998;351:356-361.
- Murphy TV, Gargiullo PM, Massoudi MS, et al. Intussusception among infants given an oral rotavirus vaccine. N Engl J Med. 2002;344:564-572.
- Kramarz P, France EK, Destefano F, et al. Population-based study of rotavirus vaccination and intussusception. Pediatr Infect Dis J. 2001;20:410-416.
- Meyer PA, Seward JF, Jumaan AO, et al. Varicella mortality: Trends before vaccine licensure in the United States, 1974-1994. J Infect Dis. 2000;182:383-390.
- Davies P, Chapman S, Leask J. Antivaccination activists on the World Wide Web. Arch Dis Child. 2002;87:22-25.
[Introduction]
[Truths About Vaccines]
[Myths Regarding Immunization]
[Communication in the Physician's
Office]
[Matching Communication
Styles with Parent Personalities]