No. Carefully performed scientific studies show that vaccines do not cause diabetes or increase a person’s risk of developing diabetes. In 2002, the Institute of Medicine reviewed the existing studies and released a report concluding that the scientific evidence favors rejection of the theory that immunizations cause diabetes. The only evidence suggesting a relationship between vaccination and diabetes comes from Dr. John B. Classen, who has suggested that certain vaccines if given at birth may decrease the occurrence of diabetes, whereas if initial vaccination is performed after 2 months of age the occurrence of diabetes increases. Dr. Classen’s studies have a number of limitations and have not been verified by other researchers.