EXPERIMENTAL STUDIES OF THE NASOPHARYNGEAL SECRETIONS FROM INFLUENZA PATIENTS : VII. SEROLOGICAL REACTIONS.

Cultivation of Bacterium pneumosintes in the collodion sac dialysate of a tissue medium produces an antigen suitable for serological tests. Injection of dialysate cultures of Bacterium pneumosintes into rabbits results in the production of antibodies demonstrable by agglutination, precipitation, complement fixation, and phagocytic reactions. Four strains of Bacterium pneumosintes, three from the first epidemic influenzal wave (1918-19) and one from the second (1920), show identical antigenic characters. The blood serum of rabbits experimentally injected with the glycerolated active material of rabbit passages contains specific agglutinins for Bacterium pneumosintes, whereas normal rabbit serum does not.