Quote from Public Health Reports, Jan 10, 1919:
SOME INTERESTING THOUGH UNSUCCESSFUL ATTEMPTS TO TRANSMIT INFLUENZA EXPERIMENTALLY
These experiments were carried on by the United States Public Health Service… The subjects of experiment were 68 volunteers from the United States Naval Detention Training Camp, Deer Island, Boston. These volunteers had been exposed in some degree to an epidemic of influenza at the training camp or at some station prior to coming to Deer Island; 47 of the men were without history of an attack of influenza during the recent epidemic and 39 of these were without history of an attack of such illness at any time during their lives.
The experiments consisted of inoculations with pure cultures of Pfeiffers baciilus, with secretions from the upper respiratory passages, and with blood from typical cases of influenza. The study was begun on November 13 with an experiment in which a suspension of a freshly isolated culture of Pfeiffers bacillus was instilled into the nose of each of 3 nonimmunes and into 3 controls who had a history of an attack in the present epidemic. None of these volunteers showed any reaction following this inoculation. Another experiment was made at a later date with a suspension of a number of different pure cultures of Pfeiffers bacillus, of which 4 were recently isolated. Ten presumably nonimmune volunteers were inoculated, with the same negative results.
Three sets of experiments were made with secretions, both unfiltered and filtered, from the upper respiratory tract of typical cases of influenza in the active stage of the disease. In these experiments a total of 30 men were subjected to inoculation by means of spray, swab, or both, of the nose and throat. The interval elapsing between securing secretions from the donors and inoculation of the volunteers was progressively reduced in these experiments so that in the third of the series the interval at most was 30 seconds. In no instance was an attack of influenza produced in any one of the subjects. An experiment was made in which the members of one of the groups of volunteers which had been subjected to inoculation with secretions were exposed to a group of cases of influenza in the active stage of the disease in a manner intended to simulate conditions which in nature are supposed to favor the transmission of the disease. Each of this group of 10 volunteers came into close association for a few minutes with each of 10 selected cases of influenza in the wards of the Chelsea Naval Hospital. At the time the volunteers were exposed to this infection the cases were from 10 to 84 hours from the onset of their illness and 4 of them were not over 24 hours after the onset. Each volunteer conversed a few minutes with each of the selected patients, who were requested to, and coughed into the face of each volunteer in turn, so that each volunteer was exposed in this manner to all 10 cases. The total exposure amounted to about three-quarters of an hour for each volunteer. None of these volunteers developed any symptoms of influenza following this experiment.