Answer:
The correct order would be:
A vaccine introduces a weakened flu virus into the body.
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The immune system identifies antigens on the weakened flu virus.
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Antibodies are produced, which bind to the weakened flu virus and signal immune cells to destroy it.
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The actual flu virus enters the body, and lymphocytes recognize the antigens.
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Antibodies are quickly produced and allow the body to fight off the infection.
Vaccination or immunization is the process which helps in developing the immunity (adaptive) against a particular pathogen or microorganism.
It includes the administration of antigen, weakened or heat-killed microorganism (such as flu virus) into the patients body. Body's immune system produces naive B and T cells to eliminate the antigen.
This encounter enables the immune system to produce memory B and T cells against that particular pathogen.
In future, whenever the same antigen enters the body, the immune system gets activated quickly due to the presence of memory cells. It enables the body to produce more effective secondary response against the pathogen.
