Affiliation: | aDepartment of Molecular Medicine, National Public Health Institute, Biomedicum, P.O. Box 104, FI-00251 Helsinki, Finland bDepartment of Viral Diseases and Immunology, National Public Health Institute, Finland cOrion Pharma, Espoo, Finland dDepartment of Public Health, University of Helsinki, Finland eDepartment of Medical Microbiology, University of Oulu, Finland |