The virus spread through respiratory tract, proliferate in local lymph nodes, and spread through the body via viremia. The most serious problem with rubella virus infection is that it can spread vertically and lead to congenital infection of the fetus. Pregnant women infected with rubella virus is very harmful to the fetus, can lead to miscarriage or stillbirth. The virus can also cause congenital rubella syndrome, which is mainly caused by congenital defects in infants, and is manifested as congenital deafness, congenital heart disease, cataracts and other malformations after birth, as well as other rubella syndromes, such as large liver, jaundice hepatitis, meningitis, pneumonia and so on. The level of IgG antibodies in the serum of the body indicates whether the body has been infected with rubella virus or whether the rubella virus vaccine has been injected.