CUMULATIVE INCIDENCE OF CHILDHOOD-ONSET IDDM IS UNAFFECTED BY PERTUSSIS IMMUNIZATION

OBJECTIVE - To identify a possible effect of pertussis vaccination in infancy on the risk for developing human IDDM. RESEARCH DESIGN AND MET HODS - A comparison was made of the cumulative incidence of IDDM in ch ildren age 0-12 years between two birth cohorts born before pertussis vaccination and two birth cohorts born after pertussis vaccination had been excluded from the Swedish national immunization program. The Swe dish Childhood Diabetes registry was used to identify cases of IDDM. Y early nurse reports on administered vaccines were used to determine co verage for diphtheria/tetanus/pertussis (DTP) and diphtheria/tetanus ( DT) vaccines. Pertussis vaccine coverage was estimated based on number of doses of vaccine made available on license. RESULTS - No differenc e in cumulative incidence rate of IDDM up to the age of 12 years was f ound when the birth cohorts for 1978 and 1979 with high DTP vaccinatio n coverage were compared with the cohorts of 1980 and 1981 with low pe rtussis vaccination coverage. CONCLUSIONS - The comparison of the cumu lative incidence of IDDM, up to the age of 12 years, in birth cohorts with high and low exposure to pertussis vaccine does not support the h ypothesis that pertussis could induce autoimmunity to the beta-cell th at may lead to IDDM.