Diphtheria Immunization by Three and Four Injections of Toxin-Antitoxin

Abstract

Development of immunity against diphtheria was studied on 1242 children. Of 336 receiving 3 injections of diphtheria toxin-antitoxin (TA), 64% developed immunity at the end of the 1st yr. and 85% at the end of the 2nd. Of 946 receiving 4 injections of TA of the same preparation, 74% developed immunity at the end of the 1st yr. and 92% at the end of the 2nd. Because of the high % of immunity developed in children during the 2nd yr. after immunization, the Schick test, the author believes, need not be given as a routine procedure at the end of the 1st yr., if at all, after administration of 4 injections of TA.