Rubella virus antibody IgG is a marker of previous infection with rubella virus. If the IgG is negative, it indicates that the person has not been infected with rubella virus before. There are two main types of rubella virus antibodies, IgM and IgG. If IgM is negative and IgG is also negative, then there is no previous infection with rubella virus. If the IgM is positive and the IgG is negative, then it is indicative of a recent rubella virus infection, which also needs to be combined with the patient’s clinical symptoms for a comprehensive analysis. If there are associated clinical symptoms of rubella virus and the associated antibody IgM is positive, the diagnosis of rubella virus infection is made.