Question

Scientists use vaccines to trigger the body's adaptive immune system ____ second line of defense for the body.

A) As the first
B) As the third
C) As the fourth
D) As the last

Answer 1

The adaptive immune system is triggered by vaccines as the third line of defense against pathogens, offering a highly specific response with a memory component for faster reactivity upon future exposure.

Step-by-step explanation:

Scientists use vaccines to trigger the body's adaptive immune system as the third line of defense for the body. The immune system's first line of defense incorporates physical and chemical barriers that act nonspecifically against pathogens. The second line involves inflammatory and fever responses, as well as other cellular and chemical defenses of the innate immune system. The adaptive immune system, which includes the process of vaccination, is highly specific and offers a memory component that enables a faster and stronger response upon re-exposure to the same pathogen. Vaccination is a form of artificially acquired active immunity that stimulates the adaptive immune defenses, promoting memory cell production.