How do vaccines help?
The idea behind vaccination is to give you immunity to a disease before it has a chance to make you sick. Vaccines are made from the same germs (or parts of them) that cause disease — measles vaccine is made from measles virus, for instance, and Haemophilus influenzae type B (Hib) vaccine is made from parts of the Hib bacteria. But the germs in vaccines are either killed or weakened to reduce the risk that they will make you sick.The vaccines containing these weakened or killed germs are introduced into your body, usually by injection. Your immune system reacts to the vaccine the same as it would if it were being invaded by the disease — by making antibodies. The antibodies destroy the vaccine germs just as they would the disease germs. They stay in your body, giving you immunity. If you are ever exposed to the real disease, the antibodies will be there to protect you.
