Diphtheria Immunization with Fluid Toxoid and Alum-Precipitated Toxoid

Abstract

An investigation has been made on the height and duration of the antitoxin response following injn. with fluid or alum-precipitated toxoid in 2,487 free-living children from rural schools and communities in Saginaw County, Michigan. The antitoxin response of children to several diphtheria-immunization procedures was detd. In the decreasing order of the response they induce in children having less than 0.001 unit of antitoxin per ml. of serum at the time of injn., they are, under the conditions of the study: 2 doses of alum-precipitated toxoid at 3-week interval, 3 doses of fluid toxoid at 3-week interval, 1 dose of alum-precipitated toxoid, 2 doses of fluid toxoid at 3-week interval, and 1 dose fluid toxoid. The study emphasizes the comparatively poor antitoxin response to 2 injs. of fluid toxoid for the 3-week interval and justifies the discontinuance of this procedure for immunization against diphtheria. The study also suggests the Schick test may be omitted in routine immunization.