The present disclosure an in vitro method of assaying the stimulation of a cytokine storm response comprising the steps of: a. co-culturing PBMCs and matched differentiated endothelial cells to provide a system representative of human responses in vivo, and b. exposing the co-cultured cell system to a test agent, c. analyzing the system for the presence of one or more cytokines released after exposing the co-culture system to said test agent, and d. optionally evaluating the response to the test agent in comparison to a response to one or more control agents.
