Waerlop G, Leroux-Roels G, Lambe T, Bellamy D, Medaglini D, Pettini E, Cox RJ, Trieu M-C, Davies R, Bredholt G, Montomoli E, Gianchecchi E and Clement F Harmonization and qualification of an IFN-γ Enzyme-Linked ImmunoSpot assay (ELISPOT) to measure influenza-specific cell-mediated immunity within the FLUCOP consortium. Front. Immunol. 2022 13:984642.