Introducing the ESAT-6 free IGRA, a companion diagnostic for TB vaccines based on ESAT-6. by Ruhwald, M, de Thurah, L, Kuchaka, D, Zaher, MR, Salman, AM, Abdel-Ghaffar, A-R, Shoukry, FA, Michelsen, SW, Soborg, B, Blauenfeldt, T, Mpagama, S, Hoff, ST, Agger, EM, Rosenkrands, I, Aagard, C, Kibiki, G, El-Sheikh, N, Andersen, P