Introduction and Methods
A "double-blind" field trial of the alum-precipitated, concentrated, inactivated measles vaccine developed by Warren1,2 was carried out in the kindergartens and first grades of 15 schools in Buffalo beginning March 20, 1961.3 A total of 330 children received vaccine and 319 placebo. Vaccine and placebo were administered intramuscularly in 3 doses of 0.5 cc. The first 2 injections were a week apart, and the third was given 4 weeks after the first. Within each classroom, study participants were alternated between vaccine and placebo groups.Serologic studies were carried out on a sample of 40 children. Measles surveillance was begun at the time of the first injection and continued until the closing of school on June 23.
Comparison of the vaccine and placebo groups with respect to age, race, sex, socioeconomic status, and number of individuals in each household under 15 years of age revealed