A rubella blood test checks to see if you have antibodies to the rubella virus. Antibodies are proteins your immune system makes to help fight infections and keep you from getting sick. They're targeted to specific germs, viruses, and other invaders. Your doctor can tell a lot from the type of antibodies that you have in your blood.
IgM is first on the scene after you get rubella. It sticks around for 7 to 10 days in adults and up to a year in newborns. You'll get this test if your doctor thinks you may have rubella. You might need to have your blood tested in a public health lab in your state.
