the evidence is inadequate to accept or reject a causal relation between the vaccine and death resulting from that adverse event.
The committee explored the possibility that vaccines may cause death by mechanisms other than vaccine-strain viral infection or an adverse event that itself is causally related to vaccine administration. The committee considered whether it might have overlooked possible vaccine-related mechanisms or pathways that could lead to death. The committee was unable to hypothesize such causes. However, had the committee identified reports of death following vaccination that did not fall into any of the other six categories, de facto those reports would have been placed into this category and causality would have been assessed for those reports. The committee found no reports of death that could be placed in this category, either in theory or by exclusion from the other causes listed above.
The preponderance of data concerning death as an adverse consequence of vaccination comes from passive surveillance systems. The committee made a concerted effort to evaluate these data. The number of reports in VAERS of death in temporal association with vaccination has been the topic of presentations to the Advisory Commission on Childhood Vaccines (ACCV), the Advisory Committee on Immunization Practices, an FDA-sponsored workshop on contraindications to vaccination, a public session regarding changes to the Vaccine Injury Table, and the Vaccine Safety Committee of the Institute of Medicine. Because of this interest, because VAERS has a number of advantages over its predecessor data bases (the Spontaneous Reporting System [SRS], which was run by the FDA, and MSAEFI, which was run by the CDC), and because VAERS contains reports of reactions to hepatitis B vaccine (particularly in infants and children) and H. influenzae type b vaccine (which would be scarce in MSAEFI and SRS because of the recent licensure of these vaccines), the committee focused its investigations of reports to the U.S. government-run passive surveillance systems of death after vaccination on the information contained in VAERS. A description of VAERS and a discussion of its strengths and weaknesses will help in the analysis of the data that follow.