The use of hyperimmune sera for treatment or prophylaxis is referred to as "passive immunization". This approach is used when allowing the development of a natural immune response would take too long and directly threaten patient survival. This type of immunity is of sho duration and has no memory component. Ref: Levinson W. (2012). Chapter 57. Immunity. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.