What Is Antibody Testing? Antibodies (also called immunoglobulins) are proteins made by the immune system. Their job is to recognize and get rid of germs. After they're made, antibodies usually stay in our bodies in case we have to fight the same germ again. Antibody testing lets doctors look for antibodies in blood. This sometimes can show if a person was infected by a virus or other germ in the past. What Is Antibody Testing for Coronavirus (COVID-19)? Scientists have developed antibody tests for coronavirus (COVID-19). Testing a small blood sample lets doctors look for antibodies that a person's body may have made to fight the virus. Some of these tests work better than others. The virus that causes COVID-19 is only one type of coronavirus — other types can cause colds. Sometimes, the tests can't tell the difference between COVID-19 and the other types of coronaviruses. Also, doctors don't know if having antibodies to coronavirus (COVID-19) protects a person from being infected by the virus again. If there is protection, they don't yet know how long it might last. Talk to your doctor to see if antibody testing for coronavirus (COVID-19) is right for you or your children. How Is Antibody Testing for Coronavirus (COVID-19) Done? An antibody test for coronavirus (COVID-19) uses a small blood sample. To get the sample, a health professional will: Clean the skin. Put an elastic band (tourniquet) above the area to get the veins to swell with blood. Insert a needle into a vein, usually in the arm inside of the elbow or on the back of the hand. Pull the blood sample into a vial or syringe. Take off the elastic band and remove the needle from the vein. Sometimes an antibody test can be done with a "fingerstick." The health professional will clean the finger, then prick the tip of it with a tiny needle (or lancet) to collect the blood. Where Can I Learn More About Coronavirus (COVID-19) and Antibody Testing? Check the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) websites for information about testing and other updates on coronavirus. Back to Articles Related Articles Understanding Coronavirus (COVID-19) Looking for information about coronavirus (COVID-19)? Our articles and videos explain what the virus is, ways to prevent it from spreading, what it means for school and learning, and much more. Read More Coronavirus (COVID-19) Pandemic: What to Do if Your Child Is Sick There's still much to learn about COVID-19. Still, parents wonder what to do if their child gets sick during the pandemic. Here's what doctors say to do if your child has coronavirus symptoms. Read More Coronavirus (COVID-19): Your Questions Answered We're learning more about coronavirus (COVID-19) every day. Here are answers to some questions you may have about symptoms, care, and protecting your family. Read More Coronavirus (COVID-19): Home Care & Precautions Anyone who is sick — even if they don't know for sure they have coronavirus (COVID-19) — should stay home unless they need medical care. This helps prevent the illness from spreading to others. Read More Coronavirus (COVID-19): Getting Tested at a Drive-Thru Testing Site A drive-thru testing site is a place where parents and children stay in the car while a health care provider does a test. Read More Helping Kids Deal With Injections and Blood Tests Blood tests and insulin injections can be a challenge for kids with diabetes and their parents. Here are some strategies for coping with these necessary procedures. Read More Immune System The immune system, composed of special cells, proteins, tissues, and organs that protect against germs and microorganisms, is the body's defense against disease. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.