deaths temporally associated with vaccine administration but clearly caused by something other than the vaccine;
deaths classified as sudden infant death syndrome (SIDS);
deaths that are a consequence of vaccine-strain viral infection (applies to measles, mumps, or oral polio vaccine [OPV] for this report);
deaths that are a consequence of an adverse event that itself is causally related to a vaccine reviewed in this report; and
deaths temporally associated with vaccine administration and the cause of death is other than those listed above.
The reports from passive surveillance systems accessed by the committee vary in the quantity and quality of the information that they contain. Many of the reports contained phrases such as "died" or "found dead at baby-sitter's." Reports with more information frequently had no additional documentation submitted with them, so assessment of the diagnosis was not possible. The information in VAERS is discussed below in great detail. The published literature contains reports of deaths following immunization that lack sufficient information for a causality assessment as well. This is most common in uncontrolled observational studies intended to give a broad picture of the results of immunization campaigns.
This category includes a wide range of contamination or handling problems; vaccines, like any other pharmaceutical agent, are subject to mishandling that might, in extreme cases, lead to death. The Cutter incident is a well-known example of vaccine contamination caused by errors in quality control by the manufacturer and lack of clear guidelines from a regulatory agency; 60 vaccine recipients and 89 contacts of recipients contracted polio as a result of contamination of two production pools of inactivated polio vaccine (IPV) with live virus in 1955 (Nathanson and Langmuir, 1963). Contamination can occur at a more local level. Sokhey (1991) reported several deaths following administration of measles vaccine in India. The report lists the cause of death as "toxic shock syndrome" and notes that contamination was likely because syringes and needles were reused and the sterilization procedures were unsatisfactory. Staphylococcus aureus was