Scientists produce many kinds of vaccines. Live
vaccines contain a weakened form of a virus or
bacteria. The weakened germs cannot reproduce
easily. They will not make a person sick. Scientists
also make inactivated vaccines. The germs in
these vaccines are killed with heat or chemicals.
For this reason, inactivated vaccines are easier to
store and handle.
HOW A VACCINE WORKS
Vaccine Germs
Antibodies
Dead or weakened
germs in the vaccine
enter a person’s body.
The body responds to
the vaccine as it would
to an infection.
Antibodies remain in the
body to fight the same
germs in the future.
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