226 SCHROEDER 



attempt be made to immunize cattle in a vampire bat rabies epidemic 

 area, using as antigen chicken-embryo-adapted and modified live virus 

 vaccine. Thousands of cattle in Guatemala, Mexico, Honduras, Costa 

 Rica and Nicaragua have now been successfully immunized. This form of 

 vaccine has given complete protection without a report of a single vac- 

 cinated animal coming down with rabies from any source. Currently the 

 dose of Flury-strain chick-embryo rabies live-virus vaccine is 15cc of a 

 20% suspension injected intramuscularly (Table II). 



TABLE 2 



Mortality Ratio of Cattle Vaccinated with Avianized Rabies 

 Vaccine and Challenged Five Months Later with Street 



Rabies Virus 



Dose 



(ml.) 



7.5 

 15.0 



7.5 

 15.0 



*Challenge — 1 ml. street rabies virus in each masseter muscle. This is a severe 

 challenge far exceeding field exposure. 

 **Recorded forty-eight dajs after challenge inoculation. 



In 1948 Johnson reported that from an historical standpoint "Der- 

 riengue" or vampire bat paralytic rabies has been known in Mexico for a 

 minimum of thirty seven years and possibly longer. He showed by cross 

 neutralization, complement fixation, and protection tests, that the virus 

 he recovered in Mexico from vampire bats and from cattle was rabies. 



In May, 1945, the San Diego Zoo lost a long-time resident, an adult 

 female Masai giraffe carrjang a 5 months calf. The symptoms were typi- 

 cal of encephalitis. Howard Ball, M. D., Pathologist and member of the 

 Research Committee of the Zoological Hospital and Biological Research 

 Institute of the Zoological Society of San Diego, conducted an autopsy. 

 He sent specimens of brain tissue in glycerine to Edwin Linette, M. D., 

 State Virus Laboratory, California State Department of Health, Berke- 

 ley. The findings of that laboratory are recorded in the Bulletin of the 

 Pan American Sanitary Bureau, WHO, Volume 27, No. 4. Rabies virus 

 was isolated. The source of infection remains unknown. Dogs and other 



