What is a transfusion reaction?

A transfusion reaction specifically refers to a serious complication that occurs when there is an incompatibility between the blood of the donor and the recipient. This mismatch can lead to the recipient's immune system attacking the transfused blood cells, which can cause a range of symptoms, from fever and chills to more severe complications like hemolysis, kidney failure, or shock. Understanding that transfusion reactions are linked to specific immunological responses is crucial for patient safety during blood transfusions. Other options may describe mild or common occurrences related to blood donation or vaccination but do not capture the severity and clinical implications of a transfusion reaction itself.