IMMUNIZATION of infants against diphtheria, tetanus, and whooping cough.

Pnrophylaxis against diphtheria is universally recommended; prophylaxis against whooping cough is now generally accepted; and prophylaxis against tetanus has been found effective, although it has not been used routinely. The combined prophylaxis against two of the three diseases—diphtheria and tetanus—has been in use for several years.1This paper records my experience with the combined prophylaxis against the three diseases—diphtheria, tetanus and whooping cough. Theoretically, this triple immunization would present two advantages: first, possible adsorption of the toxoids and toxins by bacterial suspension, thus affording what Ramon2has called a larger "effective antigenic surface;" second, nonspecific enhancement of antigen production, termed by Ramon "antigenic synergy." As an example of antigenic enhancement produced by the mixture of a toxoid with a bacterial vaccine, the work of Schutze3is of interest. He immunized guinea pigs with mixtures of alum-precipitated diphtheria toxoid and whooping cough vaccine and reported the antigenic