The Absence of Seasonal Change in the Toxin-Producing Capacity of the Diphtheria Bacillus

Abstract

. . . There is this general impression that the best toxin cannot be produced during the summer months. The impression exists in our midst that the summer season is a poor time to make diphtheria toxin. It has been our experience, time and time again, to see good diphtheria toxin production taper off as the summer season sets in. Just what the factors are that are responsible have not been established. Toxin production seems to vary with the seasons of the year ; as for instance, in the summer, toxin production is usually very poor and manufacturers plan to make all their toxin in the winter.