Concerns have been raised about a possible association between childhood vaccinations and the development of type 1 diabetes. In mouse models, some vaccines have been demonstrated to prevent type 1 diabetes, while others appear to induce it. Rates of type 1 diabetes are higher in developed countries, where childhood immunizations are widespread. Hviid and co-investigators present population-based data regarding the incidence of type 1 diabetes and childhood vaccinations.

The authors used government data from the Danish Civil Registration System for all children born in Denmark between 1990 and 2000. During that period, general immunization schedules included vaccinations for diphtheria, tetanus, pertussis, Haemophilus influenza type B, polio, measles, mumps, and rubella. A total of 739,694 children were originally included in the data analysis, of whom 16,421 (2.2 percent) had incomplete follow-up information because of emigration, death, or other factors.

The incidence of type 1 diabetes was not statistically different based on receipt of any number of doses of any of the vaccines recorded. The analysis adjusted for possible confounding factors, including the child's weight and place of birth, and the mother's country of birth and age at childbirth. Type 1 diabetes was 40 times more likely to occur in children with at least one sibling with type 1 diabetes. The investigators also looked for any delayed clustering of type 1 diabetes cases years after vaccination but found no significant association.

The authors conclude that population-based data on more than 739,000 children indicate no association between type 1 diabetes and routine childhood vaccinations.

BILL ZEPF, M.D.