1. Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
2. Department of General Internal Medicine, University Hospitals Leuven, Leuven, Belgium
3. National Reference Centre for Streptococcus Pneumoniae, University Hospitals Leuven, Leuven, Belgium
4. Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
5. Department of Geriatric Medicine, University Hospitals Leuven, Leuven, Belgium