Vaccine Liability and Safety Revisited

IN THIS issue of the ARCHIVES, Zimmerman et al remind us that vaccine safety and liability issues remain close at hand, affecting immunization practice in various ambulatory primary care settings.¹ Not only do vaccine-related litigation concerns continue, indicating a lack of awareness of the National Vaccine Injury Compensation Program (VICP), these concerns may be limiting our ability to achieve optimal childhood immunization coverage.

The good news is . . . that there is good news. Liability protections instituted during the past 10 years have dramatically changed the litigious atmosphere surrounding immunization, and the safeguards in place today ensure the inherent safety of the products we routinely administer to our children. The recent change to the immunization schedule from oral poliovirus vaccine (OPV) to injected poliovirus vaccine (IPV) as the preferred choice, and the successful development and licensure of a new form of an acellular pertussis vaccine (DTaP) are important examples of the priority that vaccine safety is given. Unfortunately, it seems that some of the message has not gotten out despite the best efforts of the federal government, health policy groups, industry, and academia. Current knowledge of liability risk, vaccine safety science, immunization recommendations, and, more recently, effective ways to communicate vaccine benefits and risks have become integral to practice today.

In this country, vaccine safety and liability are inexorably intertwined. Why does something as traditional as vaccination attract controversy? Ironically, we are a victim of our own success.

Immunization has been one of the most successful preventive health measures ever. Yet, as the incidence of the targeted diseases diminished, vaccine "reactions" drew more attention. Concerns about whole-cell pertussis vaccine (DTP) started in the United States with the 1982 documentary DPT Vaccine Roulette. The Emmy Award winning program (strongly criticized by the American Academy of Pediatrics, Elk Grove, Ill, among others) showed severely neurologically impaired children whose conditions were all reported to be vaccine-related.² The media attention that followed led to the filing of hundreds of lawsuits against vaccine companies alleging DTP-related adverse effects. As a result, vaccine prices skyrocketed, many manufacturers ceased production, and a DTP supply "crisis" followed, with the Centers for Disease Control and Prevention (CDC), Atlanta, Ga, calling for the rationing of DTP doses for older infants and children to ensure supplies for newborns.³ Only the Congressional passage of the National Childhood Vaccine Injury Act (NCVIA) of 1986 averted long-term public health consequences. The concerns leading to passage of the act have diminished considerably, but similar themes continue to be raised by some consumer groups.

Vaccines have always been controversial, starting with Edward Jenner's development of the smallpox vaccine in the 1800s. The DTP vaccine naturally drew attention with its transient local and systemic reactions, and less common but serious adverse events such as prolonged crying, seizures, and "shock-collapse."⁴ Since it is given early in infancy, a time when genetic and developmental disorders first become apparent, it is only natural to confuse cause and effect whenever adverse events after immunization occur in children who later are diagnosed with such conditions. Examples include a child with epilepsy whose first convulsive episode was a DTP-related "febrile" seizure, or an infant diagnosed with developmental delay who experienced irritability or prolonged crying after immunization months earlier. Thus, a powerful perception of risk grew around DTP vaccine, accelerated by media reports of severely retarded children or deaths alleged to be caused by vaccines.

In an atmosphere of urgency and compromise, medical, legal, and consumer groups worked with Congress to enact the NCVIA into law. In taking this giant step into vaccine safety, the federal government instituted mandates for office record keeping, scientific studies of vaccine reactions by the Institute of Medicine (IOM), distribution of vaccine information for families and patients, and a national surveillance system to monitor adverse events. Liability was addressed with creation of the VICP, a no-fault approach to compensation that largely relies on a table of compensable injuries. Litigation would now shift to this simplified system, which provided for a presumption of vaccine causation if a condition listed on the vaccine injury table occurred within a prescribed time frame, assuming certain legal requirements were met and another cause of the illness was not present. Recognizing that science is dynamic, the VICP has updated the table twice based on IOM reports.

Operational since 1988, the program is designed to cover all routinely given childhood vaccines. The program is financed by an excise tax on every dose of covered vaccine sold. Ten vaccines are covered including those for diphtheria-tetanus-pertussis (DTaP, DTP, DTP-Hib, DT, Td, and TT), measles-mumps-rubella (MMR, MR, M, and R), polio (IPV and OPV), Haemophilus influenzae type b (Hib), hepatitis B (HBV), and varicella (VZV). All are designated by the CDC (following recommendations by its Advisory Committee on Immunization Practices) for "routine administration to children." Any newly licensed vaccine so designated will also be added to the VICP.

As of November l997, over 1100 awards had been made to families or individuals. By streamlining adjudication, the long and burdensome civil process, which in the 1980s sometimes resulted in inconsistent jury awards, was avoided. While payments cannot adequately compensate for injury suffered, these do remove the financial burden for those conditions set forth in the vaccine injury table or otherwise found to be caused by vaccines.

By most standards, the federal system has met its goals of compensating individuals, stabilizing the marketplace (supply and pricing), and reducing health care provider and manufacturer liability. New court cases have nearly disappeared, with only a small number of lawsuits filed annually against US manufacturers (Figure 1), and little evidence to suggest that those who are rejected by the federal system or who choose not to accept compensation seek court remedies elsewhere. Analysis of medical information in light of the IOM studies seems to show that vaccine-related injuries and deaths are extremely rare, with most temporally related cases caused by prenatal, metabolic, or other kinds of developmental conditions seen in children.^{5 - 7} If anything, this confirms what all of us hope and expect from products that are given routinely to healthy children and adults.

Vaccine product safety is assured by the US Food and Drug Administration's exhaustive review process, which starts with research and development and goes through to licensure and the postmarketing surveillance phase, when vaccines are being given nationwide. This last part is done principally through the Vaccine Adverse Event Reporting System (VAERS).⁸ Because large numbers of vaccines must be given to detect rare events, postmarketing surveillance is an important tool in ensuring vaccine safety. However, for a passive surveillance system such as VAERS to work, providers must be willing to report all clinically significant adverse events following administration of any vaccine, not just those mandated for reporting or known to be vaccine related.

Complementing VAERS is the Vaccine Safety Datalink Project (VSD), linking databases of computerized vaccination and medical records from 4 large West Coast health maintenance organizations.⁹ Unlike ad hoc retrospective epidemiologic studies (eg, those done for swine flu vaccine and Guillain-Barré syndrome), this infrastructure is reusable and allows more than 1 event to be studied in a less costly and more efficient manner. This more active approach allows causation assessment, something not generally possible in passive systems like VAERS, which are limited by underreporting and the lack of denominators and comparison groups. Already the VSD has added to the literature confirming that there is no increased risk of chronic arthropathy or neurologic conditions in women receiving the current RA27/3 rubella vaccine.¹⁰ While the IOM provided some reassurance, two thirds of the conditions it studied were found to have too little evidence on which to base a causation conclusion. Clearly, more research is needed, with the VSD holding promise as a critical tool for future postmarketing surveillance.

While more is known today about the inherent safety of vaccines, the uncertainty of the past is never far away. Witness the confusion surrounding the hearing loss of 1994's Miss America, initially reported in the New York Times to be caused by vaccines and later confirmed to be the result of meningitis complications from H influenzae bacteria, a condition that is now preventable with vaccines. The disquieting several days in between reminded some of the potential for widespread confusion about vaccine safety. Some even point to the hundreds of millions of dollars in VICP compensation as proof of vaccine risk, confusing this simplified legal approach of providing compensation with a scientific determination of causation. In this age of diminished disease incidence and skyrocketing information access, the importance of communicating the true risks and benefits of vaccination becomes imperative.

Immunization has its own unique set of communication challenges.¹¹ Unlike drugs or therapeutic agents, vaccines serve 1 purpose: disease prevention. Only healthy individuals receive them, beginning as early as the newborn period. Furthermore, receiving vaccines is an individual process yet conveys protection to both the recipient and the surrounding community. Thus, society has a vested interest in vaccination, which translates in most states into laws requiring immunization for school entry.

Then there is the benefit-risk ratio, which is never static. On one hand, a diminished incidence of preventable disease is welcome but shifts the balance towards risk. On the other hand, not giving vaccines will result in lost opportunities to eradicate disease (such as measles), and this risks repeats of epidemics of the past.

Fortunately, risk communication scientists have learned a great deal about what influences a person's view of risk, as well as what types of communication better inform or change behavior. Not only should message creators consider a recipient's educational level, experiences, beliefs, attitudes, and values, they should keep in mind that some react to vaccine risk based on how they perceive the risk of disease, the ability to control those risks, and the preference for one type of risk over another. Some who choose alternative health approaches (such as holistic medicine) may not accept immunization as beneficial or view the risk disproportionately. Others may dwell on sociopolitical issues, such as mandatory vaccination, informed consent, and individual rights vs societal welfare (disease protection through "herd immunity").

As the survey suggests, parent vaccine safety questions or concerns are part of today's practice. Occasionally, a parent may refuse certain vaccines or even choose to forgo immunization altogether. Beyond communicating up-to-date risk and benefit information, there is little else to do but carefully document the discussion and decision not to vaccinate. Lawsuits have also been filed for nonadministration of vaccines.

Today, vaccine risk information is for the most part communicated through use of the government's "Vaccine Information Statements," a 2-sided sheet written at the 5th- to 7th-grade level. Research shows its reading level is too high for some, and overly simplistic and incomplete for others. Multiple instruments are needed, with other resources available for the more interested parent or vaccine recipient. Every time a "covered" vaccine is administered, the provider is required by law to give the patient—or the patient's parent or guardian—the appropriate Vaccine Information Statement and ensure that he or she understands it. These are, however, only a support tool intended to facilitate, not replace, communication between providers and patients.

Providers have access to current vaccine-preventable disease and vaccine safety information through the 1997 Red Book (Report of the Committee on Infectious Diseases of the American Academy of Pediatrics), or specific recommendations of the Advisory Committee on Immunization Practices published in the "Reports and Recommendations" section of Morbidity and Mortality Weekly Report. The latter can be downloaded from the World Wide Web through CDC's home page (http://www.cdc.gov). Timely answers to specific vaccine safety questions can be obtained from CDC's National Immunization Program by accessing their home page (http://www.cdc.gov/nip), sending e-mail (nipinfo@.cdc.gov), or calling the Immunization Hotline (1-800-232-2522). Current efforts at expanding CDC's immunization outreach program include some of the educational elements recommended by Zimmerman et al¹ under "Provider Education Needs." Finally VAERS information or a reporting form can be obtained by calling 1-800-822-7967 or through the VAERS World Wide Web site (http://www.fda.gov/cber/vaers/vaers.htm).

Provider awareness of the VICP has been a program priority since enactment of the NCVIA. Through attendance and exhibitions at professional conferences held by pediatricians, family physicians, child neurologists, pediatric nurse practitioners, and nurses, the program has made some inroads in compensating individuals and communicating the program's success in limiting vaccine liability. Descriptive and scientific articles have also been published in peer-reviewed journals, such as Pediatrics, Pediatric Infectious Disease Journal, Arthritis and Rheumatism, and Public Health Reports.^{12 - 16} As these studies point out, information gaps exist, and therefore these efforts should and will continue. Anyone wishing current information or statistics on the VICP may call 1-800-338-2382 or access the Division of Vaccine Injury Compensation's home page (http://www.hrsa.dhhs.gov/bhpr/vicp).

Information availability and access notwithstanding, nothing can replace the value and trust we place in physicians and other health care providers, who must stay current with science and be prepared to address questions and concerns that are part of today's discerning, informed landscape. Ultimately, physicians are the resource who will continue to provide vaccine safety assurance as the last step in the long line of policies and procedures that makes US vaccines among the safest and most effective in the world.