Markus Maeurer1, Alimuddin Zumla2. 1. Therapeutic Immunology Division, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden. CAST, Karolinska University Hospital, Stockholm, Sweden. markus.maeurer@ki.se. 2. Division of Infection and Immunity, University College London, and NIHR Biomedical research centre, University College London Hospitals NHS Trust, London, UK.