This unit builds on basic concepts of immunology taught at level 2. It focuses on human immune responses. Topics covered in the unit include: structure and function of the immune system; antigen recognition; regulation of host immune responses; role of immune response in control of infectious pathogens; microbial immune evasion strategies; immunopathological basis of autoimmune disease; immune response in transplantation and organ rejection; and tumour biology. In addition, it addresses the immunobiological basis of vaccination and vaccine design. Laboratory classes and eTutorials are undertaken to reinforce the material taught in lectures.