1913

Béla Schick (Vienna), publishes results of experiments showing how to test children for presence or absence of diphtheria antitoxin: a positive reaction to an injection of toxin indicated the absence of antitoxin or, in other words, a susceptibility to diphtheria. Absence of a reaction = immunity to diphtheria. The “Schick test” made possible a manageable program of active immunization for diphtheria in NYC, allowing physicians to dispense with active immunization in about 70% of all cases (Hammonds, 178-81). “By 1921, 52,000 children in 44 schools in Manhattan and the Bronx were given the Schick test, retested, and those with positive reactions given injections of toxin/antitoxin” (182-183).