A vaccine is a substance that is usually given to patients before they have a disease. The vaccine causes the patient's body to produce antibodies for the disease so that if antigens for that disease ever enter their body, the immune system can fight it off easily.

What does a vaccine contain that allows the body to do this?
A.
antibiotics and other medicines
B.
hazardous chemicals
C.
weak, dead, or partial antigens
D.
complete antigens and bacteria