[1] Katholieke Univ Leuven, Dept Publ Hlth & Primary Care, EPI Ctr, Leuven, Belgium
[2] Katholieke Univ Leuven, Dept Microbiol Immunol & Transplantat, Leuven, Belgium
[3] Univ Oxford, Nuffield Dept Primary Care Hlth Sci, NIHR Community Healthcare Medtech & IVD cooperat, Oxford, England