Rubella (German measles) gives rise to a mild exanthematous illness, accompanied by few constitutional symptions, and occurs most commonly in childhood. If the infection occurs in a woman in early pregnancy however, the virus may cross the placenta to reach the fetus, in which the infection can induce birth defects. These defects may be serious and permanent and include congenital heart disease, cataract formation, deafness and mental retardation. The prevention of fetal infection, therefore, is the primary purpose of rubella immunization.
To meet the need for an international standard for anti-rubella serum for use in the assay of rubella antibodies and in the control of specific (anti-rubella) immunoglobulins, the WHO Expert Committee on Biological Standardization established the second International Reference Preparation of Anti-Rubella Serum in 1970. The Requirements for Rubella Vaccine (Live) were adopted by the Committee in 1977, with an Addendum in 1992.