title: Clustering of cases of type 1 diabetes mellitus occurring 2-4 years after vaccination is consistent with clustering after infections and progression to type 1 diabetes mellitus in autoantibody positive individuals.
abstract: OBJECTIVE
  We previously analyzed data from a hemophilus vaccine trial and identified clusters of extra cases of type 1 diabetes mellitus (T1DM) caused by the vaccine that occurred between 36 and 48 months after immunization. Published reports indicate clustering of cases of T1DM occurring approximately 2-4 years after mumps infection. Others have reported a 2-4 year delay between the onset of autoantibodies and the development of T1DM. We attempted to determine whether similar clustering of cases of T1DM occurred after immunization with vaccines other than hemophilus.
  
  
  METHODS
  We searched MEDLINE and reviewed references from published papers to find databases on the incidence of T1DM and then searched MEDLINE to determine whether changes in immunization occurred in these regions during the times the incidence of DM was being recorded.
  
  
  RESULTS
  Distinct rises in the incidence of T1DM occurred 2-4 years following the introduction of the MMR and pertussis vaccines. A drop in the incidence of T1DM was detected between 3-4 years following discontinuation of pertussis and BCG vaccines.
  
  
  CONCLUSIONS
  The identification of clusters of cases of T1DM occurring in consistent temporal time periods allowed a link between the hemophilus vaccine and T1DM to be established. The current findings indicate the there are also clusters of cases of T1DM occurring 2-4 years post-immunization with the pertussis, MMR, and BCG vaccine. The data are consistent with the occurrence of clusters following mumps infection and the progression to T1DM in patients with antipancreatic autoantibodies.
authors.affiliation: Case Immunotherapies, Inc., Baltimore, MD 21212, USA. Classen@vaccines.net
authors.forename: J B
authors.initials: JB
authors.lastname: Classen
authors.forename: D C
authors.initials: DC
authors.lastname: Classen
mesh_terms: D001323:Autoantibodies / Q000097:blood; D001500:BCG Vaccine; D002675:Child, Preschool; D016000:Cluster Analysis; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology* / Q000276:immunology; D018073:Haemophilus Vaccines; D006801:Humans; D015994:Incidence; D022542:Measles-Mumps-Rubella Vaccine; D010567:Pertussis Vaccine; D014612:Vaccines
chemical_list: D001323:Autoantibodies; D001500:BCG Vaccine; D018073:Haemophilus Vaccines; D022542:Measles-Mumps-Rubella Vaccine; D010567:Pertussis Vaccine; D014612:Vaccines