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Although vaccines cannot be used to treat a person who is sick, they can help to prevent infections. Vaccinations tell the body to create "memory cells", which will function later to create antibodies against certain pathogens. When a person is vaccinated, what are they injected with?
A. antibodies to a disease bacterium
B. live, inactive viruses
C. weakened viruses or antigens from the virus
D. blood from a person who has had the disease
C. weakened viruses or antigens from the virus