Prescriber Update Articles

Current Evidence - No Link Between Vaccination and Type 1 Diabetes Mellitus

Web site: December 1999
Prescriber Update No.19:25-27

Medsafe Editorial Team

On the basis of a postulated infectious mechanism for the development of type 1 (insulin dependent) diabetes mellitus, several studies have investigated the possibility of an association with vaccination.  To date support has not been obtained for associations between type 1 diabetes mellitus and BCG, MMR, pertussis or Haemophilus influenzae type b vaccines.

Postulated autoimmune mechanism for suggested link with vaccines
No difference in rate of BCG vaccination between cases and controls
No association with MMR, pertussis or H. Influenzae type b
References

Postulated autoimmune mechanism for suggested link with vaccines

Several researchers have postulated that type 1 (insulin dependent) diabetes mellitus may develop secondary to an abnormal immune response to some viral infections. The possibility that childhood vaccination may also be associated either negatively or positively has also been considered. The steady increase in the incidence of type 1 diabetes mellitus in children in several countries^1,2 has lent some credence to the possibility of a positive association. Studies in diabetic mice have found that Bacille Calmette-Guérin (BCG) vaccine has interrupted the development of diabetes mellitus.³ However, most studies in humans published to date have not supported the postulated negative association with BCG vaccine or the positive association with other vaccines, but rather have found evidence for no association.

No difference in rate of BCG vaccination between cases and controls

Classen and Classen⁴ studied the incidence of diabetes and the immunisation schedule in a number of developed countries and found that the countries with the lowest rates of diabetes were those with pertussis vaccine in the vaccination programme and in which infants received BCG vaccine before 2 months of age. However, 2 of the areas where neither pertussis nor BCG were part of the schedule had among the lowest annual incidence rates (Lazio and Lombardi regions of Italy with 6.5 and 6.8 cases/100,000, respectively). Further, the study did not include Finland which has the highest incidence of type 1 diabetes in children under 15 years (35.3/100,000 for 1987-89)⁵ and where BCG has been given at birth for several decades.¹

A study⁶ conducted in Québec found no difference in the overall rate of BCG vaccination in children with type 1 diabetes mellitus compared with the control group in either of 2 case series. However, in one case series, BCG vaccination did appear to delay the onset of diabetes (12.2 ± 3.5 years for vaccinated compared with 9.2 ± 4.5 years for nonvaccinated) and vaccination at birth reduced the incidence.

No association with MMR, pertussis or H. Influenzae type b

Other studies have not found an association between childhood diabetes and measles, mumps and rubella (MMR),⁷ pertussis,⁸ or Haemophilus influenzae type b⁹ vaccines. In the study of MMR vaccine, IgG class mumps antibodies were lower in the case group with diabetes than in the controls, but the significance of this difference in antibody levels was unknown. One study¹⁰ observed a protective effect from measles vaccination and an increase in risk of type 1 diabetes with increasing load of infections.

A review by the Cochrane Collaboration Vaccines Field⁵ concluded that "the papers that explored the relation between vaccination and type 1 diabetes mellitus either did not find evidence of the causal link or found evidence against such a link." Another recent review³ was in support of this conclusion. Further studies investigating this possible association are currently being conducted.¹¹

References

1. Gardner SG, Bingley PJ, Sawtell PA, et al. Rising incidence of insulin dependent diabetes in children aged under 5 years in the Oxford region: time trend analysis. BMJ 1997;315:713-7.
2. Dokheel TM, for the Pittsburgh Diabetes Epidemiology Research Group. An epidemic of childhood diabetes in the United States? Diabetes Care 1993;16:1606-11.
3. Hiltunen M, Lönnrot M, Hyöty H. Immunisation and type 1 diabetes mellitus. Drug Safety 1999;20:207-12.
4. Classen DC, Classen JB. The timing of pediatric immunisation and the risk of insulin-dependent diabetes mellitus. Infectious Dis Clin Practice 1997;6:449-54.
5. Jefferson T, Demicheli V. No evidence that vaccines cause insulin dependent diabetes mellitus. J Epidemiol Community Health 1998;52:674-5.
6. Parent M-E, Siemiatycki J, Menzies R. Bacille Calmette-Guérin vaccination and incidence of IDDM in Montreal, Canada. Diabetes Care 1997;20:767-72.
7. Hyöty H, Hiltunen M, Reunanen A, et al. Decline of mumps antibodies in Type 1 (insulin-dependent) diabetic children and a plateau in the rising incidence of Type 1 diabetes after introduction of the mumps-measles-rubella vaccine in Finland. Diabetologia 1993;36:1303-8.
8. Heijbel H, Chen RT, Dahlquist G. Cumulative incidence of childhood-onset IDDM is unaffected by pertussis immunization. Diabetes Care 1997;20:173-5.
9. Karvonen M, Cepaitis Z, Tuomiehto J. Association between type 1 diabetes and Haemophilus influenzae type b vaccination: birth cohort study. BMJ 1999;318:1169-72.
10. Blom L, Nyström L, Dahlquist G. The Swedish childhood diabetes study. Diabetologia 1991;34:176-81.
11. T Jefferson. Vaccination and its adverse effects: real or perceived. BMJ 1998;317:159-60.