A review of five years' experience with rubella vaccine in the United States.

National morbidity figures show a decline in reported rubella and congenital rubella syndrome since 1969, concurrent with widespread use of rubella vaccine. In addition, no nationwide outbreak, such as the 1963-1964 epidemic, has occurred, though on the basis of long-term secular trends, one would be expected between 1970 and 1974. Recent rubella outbreaks have occurred in unimmunized students in high schools and universities, and there appears to have been a slight upward shift in the age-specific incidence of rubella in the United States since the beginning of widespread immunization. Currently available vaccines have provided durable protection to date, and, although reinfection is known to occur following vaccination, it has not proven a risk to the pregnant woman. There is a small but significant incidence of adverse reactions and a potential risk to the woman who is vaccinated during pregnancy. These data indicate that rubella vaccines are safe and effective. They also imply that rubella vaccines, as they are currently applied, have been successful in reducing the morbidity of congenital rubella syndrome, although continued surveillance will be necessary to confirm this trend.