Affiliation: | 1. Department of Vaccine Immunology, Graduate School of Medicine, Hokkaido University , Sapporo, Japan;2. Nebuta Research Institute for Life Sciences, Aomori University , Aomori, Japan matumoto@pop.med.hokudai.ac.jp;4. Department of Vaccine Immunology, Graduate School of Medicine, Hokkaido University , Sapporo, Japan |