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The flu vaccine activates adaptive immunity. How does this occur?

The immune system
identifies antigens
on the weakened flu virus.
Antibodies are quickly
produced and allow the
body to fight off
the infection.
The actual flu virus
enters the body,
and lymphocytes recognize
the antigens.
A vaccine introduces
a weakened flu
virus into the body.
Antibodies are produced,
which bind to
the weakened flu virus
and signal immune cells
to destroy it.

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