The Cellular Effector Function group has developed, optimized, pre-validated, and validated assays that can quantify the cytotoxic cellular subsets in regard to their ability to eliminate the virus-infected cells. In this context, the Interferon Gamma (IFN-γ) Enzyme-Linked ImmunoSpot (ELISpot) has been proven to be an excellent surrogate of the cytotoxic assay to quantify the total T cell response and perform epitope mapping against many viruses. Moreover, they have implemented the detection of granzyme B (GzB) delivered by the effector cells into the target cells of interest to detect the cytotoxic activity of NK and virus-specific CD8+ T cells. They have also optimized a novel approach to quantify the elimination of infected cells by cytotoxic CD8+ T cells, NK cells, and Antibody Dependent Cellular Cytotoxicity (ADCC)-mediating antibodies using reduction in the luciferase activity as final readout. They have implemented these assays in a variety of studies to detect Cytotoxic T and NK cell responses, as well as ADCC induced by natural infections or by vaccine candidates.