Fetal risk associated with rubella vaccine: implications for vaccination of susceptible women.

The Centers for Disease Control has maintained a register of women who received rubella vaccine within three months before or three months after conception to follow prospectively the outcome of pregnancy and to quantitate the risks to the fetus from the vaccine virus. The data indicate that rubella vaccine can cross the placenta and rarely can infect the fetus. However, no abnormalities consistent with congenital rubella syndrome have been noted in 144 infants whose susceptible mothers received the RA 27/3 rubella vaccine, the only vaccine available in the United States since 1979. Although the observed risk of defects consistent with congenital rubella syndrome is zero, there is a statistical theoretic risk of a congenital rubella syndrome-like defect; the maximum theoretic risk is 2.6%. These findings indicate that vaccination of nonpregnant postpubertal women who lack either serologic proof of immunity or a written record of vaccination on or after the first birthday can be done safely and effectively. Whereas congenital rubella infection will disappear from the United States as vaccinated children enter the childbearing years, if these practices are followed elimination of congenital rubella infection will be hastened.