Congenital Rubella Syndrome
The last major epidemic of rubella in the United States occurred in 1964 and 1965, when millions of rubella cases led to 20,000 cases of infants born with congenital rubella syndrome.
Following vaccine licensure in 1969, rubella incidence declined rapidly. Each year from 1992 through 2000, fewer than 500 cases were reported; each year since 2001, fewer than 100 cases have been reported -- a 99 percent decline compared with the pre-vaccine era.
From 1995 to 2000, an average of five congenital rubella syndrome cases was reported annually; since 2001, an average of one congenital rubella syndrome case has been reported annually.
From 1997 to 2000, most people with rubella were born outside the United States. Moreover, since 1997, most women whose infants were reported to have congenital rubella syndrome were born outside the United States in countries where routine rubella vaccination programs are not used or have only recently been implemented.
From 1997 to 1999, 21 out of 26 infants reported with congenital rubella syndrome were Hispanic, and 24 out of 26 had foreign-born mothers.
Although use of rubella vaccine is not advised in pregnant women or women planning pregnancy within a 3-month period, inadvertent administration of the vaccine to pregnant women does occur.
In order to evaluate the risk to the fetus of exposure to rubella vaccine virus, a pregnancy registry was established. By April 1989, when the registry was discontinued, vaccination of 700 women with the rubella vaccine within 3 months of conception was reported.
Among the 289 women who were known to be susceptible at the time of vaccination, outcomes of pregnancy are known for 275; 83 percent delivered living infants, all 229 of whom were free of defects associated with congenital rubella syndrome. This data is consistent with results reported from other countries, suggesting that if rubella vaccine causes defects associated with congenital rubella syndrome, it does so at a very low rate.