1. Laboratory for Immunobiology, Department of Viral Diseases and Immunology, National Public Health Institute, Helsinki, Finland
2. Department of Clinical and Experimental Medicine, Division of Pediatrics and Diabetes Research Center, Linköping University, Linköping, Sweden
3. Department of Pathology, University of Florida College of Medicine, Gainesville, Florida
4. Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida