Sizable decreases have taken place in recent years in the incidence of certain communicable diseases, notably enteric infections, tuberculosis and diphtheria; the incidence of other diseases, among them measles, has remained unchanged. Public health measures for the control of measles have been entirely inadequate. No satisfactory means of active immunization has been developed; isolation of patients, placarding of homes and closing of schools have had no appreciable influence on the control of outbreaks of the disease. Nevertheless, the death rate from measles has shown a steady decline, as exemplified by the figures for Massachusetts for the years 1920 to 1936 (table 1).
The diminution in deaths from measles may be due in part to the recognition that the disease is particularly dangerous in children of preschool age and that, although almost all persons sooner or later acquire measles, needless exposure, particularly of small children, is unwarranted and should if possible