In: Biology
4. Distinguish between the following:
a. Active and passive immunity
b. Natural and artificial immunity
c. List the major types of vaccines and define Herd immunity
(a) Active immunity is the actual immunity which is gained naturally after being exposed to an antigen. It is produced by persons own cell because of exposure to different antigens It involves the memory cell which recognized the pathogen patterns. It develops after period of weeks .
Passive immunity is transfer of active humoral immunity of pre made antibodies. Antibodies are directly inected in the persons body. The injected antibodies are produced outside the body. Pathogen does not have a dorect contatct with the persons for immunity .It provides rapid immunity.
(b) Natural immunity is achieved when a person comes in contact with a disease. Natural immunity can be passive and active.
Active immunity is when a person comes in contatct with disease and develop immunity.
Passive immunity is the naturally accquired immunity conveyed to foetus by its mother during pregnancy.
Artificial immunity id the deliberately accquired immunity through vaccines and other modes.
(c) Herd immunity is protection from disease in an indirecr way that occurs when large number of individuals of the population has become immune to an infectious disease either through vaccination of immunity through previous exposure that provides protection to the individuals which are not immune.
Major types of vaccines are- live vaccine, live attenuated vaccines, killed inactivated vaccines, toxoids, cellular fractions vaccines and recombinant vaccines.