There is no demonstrated biologic plausibility to suggest a causal relation between monovalent measles vaccine and IDDM. Indeed, the available data demonstrate a decreased relative risk for IDDM in individuals who have received measles vaccination (Blom et al., 1991).
There is evidence suggesting that mumps virus infection can trigger the onset of IDDM in some individuals. Biologic plausibility data implicating the mumps virus in the pathogenesis of IDDM include (1) the association between viral infections, including mumps, and IDDM in humans, (2) the detection of circulating autoantibodies against pancreatic antigens, particularly islet cells, during convalescence from mumps infection as well as early in the course of IDDM, and (3) in vitro studies demonstrating that the wild-type mumps virus can infect human pancreatic beta cells.
Data regarding a possible association between mumps vaccine and IDDM are limited to the cases noted above of a temporal relation between mumps immunization and the onset of symptoms of IDDM (Fescharek et al., 1990; Helmke et al., 1986; Otten et al., 1984; Pawlowski and Gries, 1991; Quast et al., 1979; Sinaniotis et al., 1975; Taranger and Wiholm, 1987). It should be noted that because the etiology of IDDM may be multifactorial, any temporal relation with mumps vaccine may be because other factors (such as toxins, nutrients, or other infections) have already destroyed enough pancreatic beta cells that even minor damage by the mumps vaccine virus may trigger the onset of diabetic symptoms.
The incidence of IDDM shortly following mumps immunization of children in Sweden and Germany was at or below expected background levels (Blom et al., 1991; Fescharek et al., 1990). It should be noted, however, that most of the postulated mechanisms of the pathogenesis of IDDM (autoimmune, cumulative environmental effects, or persistent infection) suggest that there may be a prolonged interval between vaccination and the onset of symptoms of IDDM. Even if the vaccine virus were to cause IDDM by direct cytolysis of pancreatic beta cells, it will be difficult to document this by isolating the virus from pancreatic tissue since, currently, there is a very low mortality early in the course of IDDM, when the virus would most likely be present.
The evidence is inadequate to accept or reject a causal relation between measles or mumps vaccine and IDDM.