What Is an Antibody Test?
An COVID-19 Antibody Test is a screening for things called antibodies in your blood. Your body makes these when it fights an infection, like COVID-19. The same thing happens when you get a vaccine, like a flu shot. That’s how you build immunity to a virus.You may also hear it called a serology test.The antibody test isn’t checking for the virus itself. Instead, it looks to see whether your immune system -- your body’s defense against illness -- has responded to the infection.
How Does an Antibody Test Work?
A technician will take a bit of your blood, like through a finger prick. The test looks for one or both kinds of antibodies to SARS-CoV-2, the virus that causes COVID-19:
- IgM antibodies, which happen early in an infection
- IgG antibodies, which are more likely to show up later
CONTINUE READING BELOWMost people have IgG antibodies about 14 days after symptoms start. They usually stay in your blood long after the infection goes away, but we don’t know how long that is for the new coronavirus.
What’s the Difference Between a Coronavirus Test and an Antibody Test?
A coronavirus test, sometimes called a diagnostic test, looks for signs of active virus. It’s simpler and faster than an antibody test. But it tells you only if you have the virus in your body at the moment when you’re tested.An antibody test shows that you had the virus at some point in the past. It could be gone, or you could still be contagious.
Why Do We Need Antibody Testing?
You could have SARS-CoV-2 and not know it. Not everyone who gets it has symptoms. Experts hope antibody tests can give health officials a better idea of how common the virus is.Once scientists know who has had the virus, they can find out how sick it makes most people. And they can study what happens if people who've had it come into contact with it again. Along with other scientific information, this can help researchers understand who might be immune to the virus.