The unstable keeping quality of the pasteur vaccine is a very important factor to be considered.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
It is true that they have been modified and weakened by the process adopted by pasteur, but it is not impossible for such modified virus to regain its original virulence after it has been scattered broadcast by the inoculation of large herds.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler
pasteur originated and perfected a system of preventive inoculation against this disease which has greatly reduced the mortality in human subjects.
"Special Report on Diseases of Cattle"
U.S. Department of Agriculture J.R. Mohler