Antibody serology tests check for the presence or level of specific antibodies in the blood. Antibodies are proteins that your immune system makes to fight foreign substances. These substances are often pathogens, (disease-causing germs) such as viruses and bacteria. When you have an infection, your body makes antibodies that are targeted to those pathogen. These antibodies may protect you from getting another infection or from getting severe symptoms. A vaccine can also provide protection by triggering your immune system to make antibodies to pathogen.
The tests may also be used to check for certain antibodies that may be a sign of an autoimmune disease. Autoimmune diseases cause your immune system to attack your own cells, tissues, and/or organs by mistake.
Antibody serology tests are not used to diagnose diseases. They can show that you have antibodies to a disease. But they can't show if the antibodies are from a current or past infection or from a vaccination.
