HC Deb 01 March 1949 vol 462 c33W
Mr. Viant

asked the Minister of Health what is the composition of the preparation now being injected into children for immunisation against diphtheria; and whether an assurance can be given that the inoculation will not, in any case, be followed by a reaction.

Mr. Bevan

Different preparations are in use, but the basis of them all is diphtheria toxin treated with formalin and heat. I am advised that the possibility of reactions cannot entirely be ruled out, but they are very rare.