Question

Toxoid is included in which of the following?
A.Natural active acquired immunity
B.Natural passive acquired immunity
C.Artificial active acquired immunity
D.Artificial passive acquired immunity

Answer 1

Hint:Toxoids are chemical substances usually modified toxins, extracted out from pathogenic microorganisms to be used as a vaccine. They are no longer toxic but act as antigens, which means they retain the property of the formation of antibodies.

Complete answer: 1.Artificial active acquired immunity:
It is the kind of immunity or protection induced by intentional exposure of a person to antigens through a vaccine, in order to produce an active and lasting immune response. It is usually acquired through exposure to antigens in a vaccine, which are capable of stimulating the immune system to produce antibodies specifically against the antigen. The memory cells of the immune system learn to produce similar antibodies in case of an attack by the infectious agent in the future. This process is called immunization.
2.Toxoid:
Toxoids are the chemical substances, extracted out from pathogenic agents, which are weakened but capable of stimulating an immune response i.e. production of antibodies, from the immune system of the body. Toxins extracted from pathogens are called exotoxins which are highly reactive and cause disease manifestation. They are heated or treated with chemicals to weaken them and form toxoid, hence toxoids are basically weak forms of exotoxins originally produced by pathogens.
Hence, the correct answer is option C i.e. artificial active acquired immunity.

Note: Such kinds of immune responses are possible because of memory cells. Memory cells are created when the lymphocytes, which are able to remember the previous attacks by the pathogen and produce antibodies against it to protect the body, are exposed.