Just for Teenagers Immunizations. It's not about having blood taken from our arm or finger. It's not about having a skin test for tuberculosis. It's about immunity.
Immunity is our body's ability to defend itself against foreign substances like germs.
When we were brand new babies we had some immunity to germs from our moms. This is called passive immunity and is not long-lasting. For the most part, immunity is something we develop over time. We get sick from a germ, our body makes antibodies to fight the germ, the germ is defeated and dies, and the antibodies we made stay with us for life or some period of times. Then, if we have the same germ enter our body again, the antibodies made from the first infection can fight the new infection off and we don't get as sick as before or we won't get sick at all.