Diphtheria toxoid lozenges were given to eighty-eight children aged 10–12 years who had previously been immunized by parenteral injection, and the antitoxin titres before and after administration were compared with those in a similar group of forty-six children who received formol toxoid by injection.
The results showed that a course of two lozenges at an interval of 1 week was a satisfactory means of reinforcing immunity in the children. The antitoxin response was less than that after injection, but a substantial response occurred in the children with low initial titres.
It is suggested that the lozenges might replace an injection as a means of reinforcing immunity in children aged 10–12 years and that they might be a valuable means of rapidly reinforcing the immunity of a large number of children in an epidemic.
The lozenges must be given under supervision to ensure that the children allow them to dissolve slowly in their mouths.
We should like to thank Dr J. D. Abbott of the Public Health Laboratory, Manchester, for separating the sera.