This paper presents the results of H and O agglutinations on 90 serums from individuals who had received triple typhoid (TAB) vaccine and on 100 unselected serums sent in for the Wassermann test.
The serums from vaccinated individuals were furnished by members of the class in Medical Bacteriology. Histories of previous vaccination or typhoid fever were obtained and these histories were properly considered in recording results.
It was impossible to obtain histories on the second group of serums but these were regarded as representative of any random group of individuals.
All of the serums were titrated for H and O typhoid agglutinin content using the formalinized antigen recommended by Dreyer (1) and an alcoholized antigen prepared according to Gardner's (2) method. A strain of typhoid which had been isolated from the blood stream of a patient six months previously was used for the preparation of the two antigens.