Rubella or German measles is a contagious viral infection caused by the rubella virus. On exposure to the rubella virus, a person develops pinkish-red rashes, mild fever, swollen lymph nodes, runny nose, headache, and joint pain. Rubella is a droplet infection. Two antibodies whose detection is vital to confirm Rubella infection are – IgM and IgG. The antibodies remain for years in the bloodstream. The rubella ab igg test may confirm immunity towards Rubella or detect past or recent Rubella infection. It also confirms whether a person has ever been exposed to the virus or has been vaccinated. The test is done by pregnant women and would-be mothers to confirm immunity towards Rubella infection.