Acquired, (i.e. not congenital), rubella is transmitted via airborne droplet emission from the upper respiratory tract of active cases. The virus may also be present in the urine, feces and on the skin. The disease has an incubation period of 2 to 3 weeks.
There was a pandemic of rubella between 1962 and 1965, starting in Europe and spreading to the United States. In the years 1964-65, the United States had an estimated 12.5 million rubella cases. This led to 11,000 miscarriages or therapeutic abortions and 20,000 cases of congenital rubella syndrome. Of these, 2,100 died as neonates, 12,000 were deaf, 3,580 were blind and 1,800 were mentally retarded. In New York alone, CRS affected 1% of all births.
In 1969 a live attenuated virus vaccine was licensed. In the early 1970s, a triple vaccine containing attenuated measles, mumps and rubella (MRS) viruses was introduced.