Some Observations on the Use of Alum Precipitated Diphtheria Toxoid

SINCE Glenny and Barr,' in 1931, first described a method for the precipitation of diphtheria toxoid with potassium aluminum sulphate and showed its exceptional antigenic efficiency in animals, evidence has been rapidly accumulating that a single dose will change well over 90 per cent of Schick positive children to Schick negative in 8 weeks. Wells, Graham, and Havens,2 in 1932, confirmed the observations of Glenny and Barr in guinea pigs and gave the single dose injection to 98 children, all with strongly positive Schick reactions. At the end of 8 weeks all but 6 had been rendered Schick negative. Graham, Murphree, and Gill 3 obtained more than 92 per cent negative Schick reactions in 185 Schick positive children, within 2 to 4 months a-fter a single injection. Baker and Gill 4 in 197 Schick positive children (22 of whom were older than 13 years) obtained negative Schick reactions in 100 per cent after a single dose. McGinnis and Stebbins,5 using 1 dose of precipitated toxoid and working with a representative number of children, all of whom were Schick tested before and after immunization, concluded tha