TWO strains of live attenuated measles-virus vaccine have been licensed for use in the United States, the Edmonston B strain in March 1963 and the Schwarz further attenuated strain in February 1965. Both the Edmonston B and the Schwarz strain vaccines have been highly immunogenic and protective against measles.1 However, the incidence of high fever and rash has been significantly less following inoculation of the further attenuated vaccine.
A recent report by Hilleman et a12 described the development and evaluation of a new further attenuated vaccine, designated by the name of "Moraten." The present study was undertaken to compare Moraten with the Schwarz strain in regard to clinical reactions and immunogenic effect.
The studies were conducted in Winnipeg, Canada and at the Willowbrook State School, Staten Island, NY. The Winnipeg study was carried out in institutionalized children at the St. Amant Home and in home-dwelling children of the Children's Aid