How to Prepare for Expert Testimony on the Safety of Vaccination (2019)

The Centers for Disease Control and Prevention has recently announced that vaccine coverage in American children has begun to decline as more parents seek medical, religious, and so-called philosophical exemptions. The proportion of unvaccinated American children has now reached 1.3%.1 This was a depressing announcement but not surprising in view of the increase in antivaccinationism, or as it is euphemistically called, “vaccine hesitancy.” One of the reasons for the decline in vaccination became clear to me in January 2018, when I was asked to do a pro bono deposition in a case in which a father who wanted his daughter vaccinated before entering kindergarten was suing his divorced wife, who opposes vaccination. I accepted because I viewed it as a public service, and I thought I merely had to testify about the benefits of vaccination and its overall safety.However, when I arrived at the conference room where the deposition was to be conducted, I found 2 lawyers representing the mother. I later learned that 1 of the lawyers was a partner at a New York City law firm that specializes in vaccine injury and antivaccination suits. The firm represents those opposed to mandatory vaccination. As an example, it opposed a regulation in New York that would allow a child with a sexually transmitted disease to be vaccinated against human papillomavirus without parental permission.2,3That lawyer grilled me for 10 consecutive hours on subjects ranging from putative vaccine reactions, the potential dangers of adjuvants in vaccines (including aluminum), the causes of autism, possible contaminants in vaccines, and other antivaccination tropes. I was also confronted with vaccine package inserts that describe hundreds of supposed reactions and asked details about the oral polio vaccination in what was then called the Belgian Congo that I was involved in during the 1950s. Table 1 includes a sampling of the subjects about which I was questioned. The opposing attorney was clearly skilled and knowledgeable about vaccination practices. He came armed with numerous articles on the subject of vaccine safety. As someone who has been working in vaccinology since the 1950s and who is the chief editor of the textbook Vaccines, I think I know something about the subject, but I did not have articles at my fingertips and had to depend on my memory.In his questioning, the lawyer constantly referred to articles of doubtful scientific quality, and I was reminded that an appreciation of the differences between valid studies and those of poor quality is understood by scientists, but judges and lawyers may be misled by some of the thousands of articles published each year, many of which are published for profit and lack scientific integrity. This makes it difficult for lawyers and judges to distinguish truth from misrepresentation.Therefore, I am concerned about future expert witnesses in cases involving vaccine safety. It is important that they have the latest data from scientifically reliable studies. With the help of Dr Paul Offit and Heather Bodenstab, we have created a library at the Children’s Hospital of Philadelphia that contains references on vaccine safety from reliable medical literature. The library is accessible through the hospital’s Web site (vaccine.chop.edu/safety-references). This resource is designed to help expert witnesses but will also serve pediatricians who wish to inform themselves about vaccine safety.Another aspect of the questioning was related to package inserts for vaccines. On this topic, I had to agree with the opposing lawyer that they are incomplete documents written primarily (although imperfectly) to protect the manufacturers from legal attack. In addition to pertinent safety information, the package inserts list numerous putative reactions to each vaccine, as reported by physicians to the Vaccine Adverse Events Reporting System from empirical experience. The inserts say nothing about the overall safety record, which may be based on millions of subjects. The description in the inserts of crucial trials seem to imply that safety was observed only over a few days postinoculation, and they ignore the reality of longer follow-up in safety trials plus data accumulated through years of use. More should be said in the package insert about the efficacy of the vaccine. I am campaigning with the Food and Drug Administration and vaccine manufacturers to add the missing information to the package inserts. It would help if organizations such as the American Academy of Pediatrics actively supported those changes in the package circulars.Although in this case the judge ruled in favor of vaccination, I am convinced that the antivaccination movement is much better organized than the pediatric community, and if nothing is done to correct this imbalance, vaccine coverage will decrease further. It is crucial that future expert witnesses be better prepared with scientific information enabling extensive rebuttals. Just as important, they should be prepared by defense lawyers (which I was not) about how to handle questions that are not grounded in accepted science.In addition, organizations such as the American Academy of Pediatrics and the Pediatric Infectious Diseases Society should provide training to vaccine experts on how to give testimony. If possible, it would be useful to identify and train a panel of experts who would agree to present the science in vaccine-related legal contests. Moreover, they will need training to deal with the legal concept of reasonable doubt, by which a poor-quality study is used to question the overall data in favor of safety. If this is not done, lawyers such as the one I faced will have a significant negative impact on vaccination, raising costs and diminishing coverage. We must not allow our child patients to be unprotected as a result of the antivaccination movement’s specious and unfounded objections or otherwise unsound positions transmitted through the legal system like an infectious disease.