Immunization in the first month of life may explain decline in incidence of IDDM in the Netherlands

A low cumulative incidence of IDDM was reported in Dutch males born in 1962 (Diabetologia 1992: 35: 139-142) compared to males born in previous or lat er years. The cause for the decreased risk has not been previously explaine d. We propose that children born in 1962 during an European smallpox epidem ic may have received the smallpox vaccine in the first month of Life and th is may have attributed to the decreased risk of IDDM in these children. We have shown that immunization with several different vaccines starting in th e first month of life prevents diabetes in NOD mice and BE rats (Autoimunit y 1996: 24: 137-145) while immunization at birth with the BCG vaccine is as sociated with an decreased risk of IDDM in humans (Infectious Diseases in C linical Practice 1997: 6: 449-454), An even bigger decline in diabetes is s een in rodents and associated in humans when one compares immunization star ting in the first month of life to immunization starting after 2 months, si nce the later has been associated with an increased risk of IDDM, Immunizat ion studies in the past have typically followed patients for only several w eeks to determine any unplanned affects on autoimmune disease. Due to the p otential benefit of reducing the incidence of diabetes by 50% through age 1 8 we believe clinical trials are warranted to study the effect of timing of immunization on IDDM.