1. The Juvenile Diabetes Research Foundation Center for Type 1 Diabetes Prevention in Finland (T.K., A.K., A.-M.H., M.Ku., P.Ku., K.S., T.S., P.Ke., J.I., O.S., M.Kn.), FIN-33014 Tampere
2. Department of Pediatrics, Medical School, University of Tampere (T.K., M.Ku., M.Kn.), and Tampere University Hospital, FIN-33014 Tampere
3. Department of Pediatrics (A.K., T.S., P.Ke., J.I., O.S.) FIN-20520 Turku
4. University of Oulu (A.-M.H., P.Ku., K.S.), FIN-90220 Oulu
5. Department of Virology (J.I.), University of Turku, FIN-20520 Turku
6. Hospital for Children and Adolescents (M.Kn.), University of Helsinki, FIN-00029 Helsinki, Finland