Question: Why does the delayed hypersensitivity reaction take a longer period of time to occur compared to the immediate hypersensitivity reaction? Question Answer a. Delayed hypersensitivity reaction relies on the production of antigen-specific antibodies which takes time. b. Delayed hypersensitivity reaction relies on cell-mediated immunity which takes time. c. Delayed hypersensitivity reaction requires a sensitization period as a prerequisite to forming memory cells. d. Delayed hypersensitivity reaction involves numerous immune effectors which take time to coordinate.