Risky Business: Challenges in Vaccine Risk Communication

Abstract

Concern over vaccine safety has been a major determinant of immunization policy—from passage of the Biologics Control Act in 1902 to the recent American Academy of Pediatrics (AAP) and Advisory Committee on Immunization Practices (ACIP) recommendations for expanded use of inactivated polio (IPV) and acellular pertussis vaccines.1-4 With the availability of new vaccines and vaccination options comes the challenge of how best to communicate these options to patients and their parents. Lessons from the field of risk communication on predictors of risk acceptability and vaccination decision heuristics provide insight into why some parents resist vaccination. This article provides a historical perspective on vaccine adverse events and applies lessons from risk communication research to help physicians improve their ability to discuss vaccine risks.Immunizations have been described as the single most effective health intervention after clean water and sewage disposal,5 and have an extraordinary safety record. However, public policy has long reflected concern for the safety of vaccines and related biologics. In 1902, Congress passed the Biologics Control Act in response to the death of 13 children who had received injections of diphtheria antitoxin contaminated with tetanus toxin.6 This act required biologics to be manufactured in a manner that assured their safety, purity, and potency. Responsibility for these regulations was assigned originally to the Hygienic Laboratory of the Public Health Service, which evolved into the National Institutes of Health. The regulation of biologics including vaccines was transferred to the Food and Drug Administration (FDA) in 1972.The first published accounts of serious adverse events after whole cell pertussis vaccine occurred in 1933 with Madsen's7 report of two deaths within 48 hours of immunization, and in 1948 with the report in Pediatrics by Byers and Moll8 of encephalopathy after diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine (DTwP). In 1955 the Cutter incident occurred, in which incompletely inactivated Salk vaccine was associated with over 200 cases of paralytic poliomyelitis.9 By the 1970s the incidence of many vaccine-preventable diseases had decreased significantly and concern over safety of whole cell pertussis vaccine surfaced in Japan and Europe.10 Pertussis immunization rates plummeted in several countries. Outbreaks of pertussis followed, leading to the development of an acellular pertussis vaccine (DTaP) in Japan.11The pertussis debate raging in Europe and Japan reached the United States in 1982, when the Emmy Award-winning television program,DPT: Vaccine Roulette, was aired with allegations of serious neurologic sequelae after DTwP.12 This was followed by the publication of Coulter and Fisher's book, DPT: A Shot in the Dark, in 1986.13 A dramatic increase in diphtheria, tetanus, and pertussis vaccine (DTP) litigation led to the withdrawal of several manufacturers from the marketplace. The Centers for Disease Control and Prevention (CDC) began stockpiling DTP vaccine as a shortage loomed. With the nation's health at stake, the National Childhood Vaccine Injury Act of 1986 (NCVIA) was passed,14after a collaborative effort involving the AAP, consumer advocacy groups, and others. This act included several provisions relevant to vaccine safety, creating the National Vaccine Injury Compensation Program (VICP) and the Vaccine Adverse Event Reporting System and mandating comprehensive reviews of vaccine-related adverse events by the Institute of Medicine (IOM) and the development of vaccine information materials.The expanded role of DTaP and IPV vaccines in childhood immunizations is in direct response to vaccine safety considerations. Concerns about local and systemic reactions prompted the recent revisions to the ACIP and AAP acellular pertussis vaccine recommendations, despite the lack of data establishing conclusively a causal link between DTwP and serious sequelae.15 After over a decade of research to develop less reactogenic pertussis vaccines for infants, the FDA licensed acellular pertussis vaccines for the fourth and fifth doses in 1992 and for the primary series in 1996.16 DTaP is now the preferred product, with DTwP an acceptable alternative during the transition period.24Since 1980, an average of 8 to 9 cases of paralytic polio per year have been associated with the live, trivalent oral polio vaccine (OPV) in the United States, either through direct receipt or contact with a recipient.3 In 1994, the Western Hemisphere was certified by the World Health Organization to be free of indigenous wild polio.17 The greatly diminished risk of acquired paralytic polio from wild poliovirus, either indigenous or imported, prompted a reevaluation of the risks of OPV-associated paralytic polio. After much debate, the AAP and ACIP have moved toward expanded use of IPV.13 With the availability of new options comes the challenge of how to communic