Question

Vaccines are composed of ________ that stimulate an active immunity to the pathogen.

A) the non-pathogenic portion of the microorganism
B) the pathogenic portion of the microorganism
C) antibodies to a microorganism
D) memory B cells that respond to a microorganism
E) memory T cells that respond to a microorganism

Answer 1

Vaccines are composed of the A) non-pathogenic portion of the microorganism. Hence, option A) is correct.

Step-by-step explanation:

Vaccines are composed of non-pathogenic portion of the microorganism that stimulate an active immunity to the pathogen.

Vaccination involves the delivery of noninfectious antigens derived from known pathogens into the person's blood, which are then moved to the cell surface of antigen-presenting cells.

This direct cell-to-cell contact initiates a series of events that leads to production of antibodies by B lymphocytes. Memory cells are generated, providing future protection against the actual disease.