1. Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, Umeå, Sweden
2. Department of Public Health and Caring Sciences, Geriatric Medicine, Uppsala University, Uppsala, Sweden
3. Department of Clinical Microbiology, Virology, Umeå University, Umeå, Sweden
4. Centre for Demographic and Ageing Research, Umeå University, Umeå, Sweden
5. Department of Odontology, Umeå University, Umeå, Sweden
6. Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
7. Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden