72 
North Carolina Experiment Station 
d’Herelle (4) has reported the presence of a bacteriophage against avian 
typhoid in his experimental work on this phenomena as recorded in “The 
Bacteriophage.” The role of the bacteriophage as a prophylactic agent under 
natural conditions is problematical, but it is highly probable that d’Herelle’s 
principle is active in some of the birds that resist the disease. A bacterio¬ 
phage was successfully recovered in two instances in the artificial infection 
work in this laboratory from the fecal material of birds which threw off the 
disease. The virulence of the bacteriophage isolated was two plus against 
E. sanguinaria. 
Vaccination of birds with avian typhoid vaccine failed to demonstrate an 
upset of body temperature, though a depressing effect was sometimes noticed 
in the field. In the matter of egg production, there was manifested a de¬ 
cided decline in production for seven days after vaccination, the decline 
being greatest the first three days. Normal production was resumed in from 
7 to 10 days, as shown in Figure 30. 
The possibility of immunity being established in the domestic fowl against 
avian typhoid by the use of vaccines prepared for human usage with the 
Bacillus typhosus has been considered, but in an experiment carried out in 
conjunction with this work such immunity could not be demonstrated. Two 
adult birds were vaccinated with the vaccine for humans, one receiving one 
vaccination of 1 cc. and the second bird two vaccinations 7 days apart. Both 
of these birds succumbed from infection with avian typhoid, and the causa¬ 
tive organism was recovered. A similar attempt was made to immunize 
with the triplex vaccine for humans. The bird receiving the single vacci¬ 
nation succumbed to infection with E. sanguinaria, the bird receiving the 
double vaccination contracted the disease, but recovered. 
