This article describes the In Vitro tests developed to date in the diagnosis of COVID‐19 vaccine hypersensitivity: (1) analysis of specific IgE and IgG, (2) Basophil Activation Test, (3) Histamine Release Test, (4) IgM‐dependent complement activation, (5) Lymphocyte Transformation Test, (6) Flow cytometry T‐Cell markers, (7) Th1/Th2 cytokines concentration in cell culture. This evidence concerns the gene CD40LG and COVID-19.