Vaccination against hog cholera has been practiced less than 60 years. Recently, we've outlawed "live" virus and substituted "modified live" virus vaccines. Now, we're aiming to eradicate this costly disease.
Speer, Maynard L. D.V.M.
"What's Being Done About Hog Cholera?,"
Iowa Farm Science: Vol. 17
, Article 4.
Available at: https://lib.dr.iastate.edu/farmscience/vol17/iss2/4