Rubella IgA is a blood test that detects the presence of immunoglobulin A antibodies against the rubella virus. This test is used to diagnose a current or recent rubella infection. Results of the test can also help determine immunity to rubella, which is important for pregnant women and individuals who may be in contact with pregnant women. The test requires a blood sample and is typically performed in a laboratory. Rubella IgA is a reliable and accurate way to diagnose and monitor rubella infections.