Clustering of Cases of IDDM 2 to 4 Years after Hepatitis B Immunization is Consistent with Clustering after Infections and Progression to IDDM in Autoantibody Positive Individuals

Background: Previous studies demonstrated clusters of cases of IDDM occurring 24 to 48 months after immu- nization with the hemophilus, pertussis and combined measles mumps rubella vaccines. Data was analyzed to determine if similar clustering of cases of IDDM occurred after immunization with the hepatitis B vaccine. Methods: Data on the inci- dence of IDDM from hepatitis B immunized and unimmunized cohorts of children was analyzed for the presence of clus- ters occurring after hepatitis B immunization. Results: Data from Italy, France, and New Zealand indicated rises in the in- cidence of IDDM occurred between 24 to 48 months after the introduction of the hepatitis B immunization in young chil- dren. Conclusion: Several different vaccines as well as infections with natural mumps virus are followed by clusters of cases of IDDM that occur about 24 to 48 months after immunization. This suggests a similar mechanism of action, possi- bly the triggering of a progressive autoimmune phenomenon.