﻿126 Tf^^ Philippine Journal of Science m* 



herein, there has come to notice the work of Holmes (5) which 

 gives additional information regarding the overestimation of 

 value of serum from hyperimmunized animals. He concludes 

 that the serum obtained after natural recovery or after an im- 

 munizing reaction is little inferior in potency to that taken after 

 the process of hyperimmunization. 



Holmes further points out that satisfactory virulent blood 

 may be obtained from an animal suffering a modified attack due 

 to the injection of serum. Thus, the animals producing virulent 

 blood recover, where formerly they were sacrificed. 



The work of the present writers was undertaken with a view 

 of reducing the cost of serum to a point that would warrant more 

 extensive use of simultaneous inoculation. The serum formerly 

 produced by the Bureau of Agriculture cost, delivered in the 

 field, 24 pesos ' per liter. That this is not excessive is shown by 

 the fact that in the Transvaal the cost was 25 pesos per liter. 

 Small quantities purchased by the Bureau of Agriculture from 

 the Pasteur Institute at Nha-Trang, French Indo-China and from 

 the Experiment Station for Animal Diseases, Tokyo, Japan, 

 were charged for at the rate of 47.89 pesos and 34.40 pesos per 

 liter, respectively. With serum costing 24 pesos per liter and 

 with the doses employed by us, the expense in simultaneous 

 inoculation for the one item of serum would slightly exceed 8 

 pesos per animal. 



In deciding to try the use of serum from animals that had 

 just been immunized instead of employing expensive serum from 

 the so-called hyperimmunized animals, we were guided by 

 several considerations. One of us, when superintendent of the 

 serum laboratory of the Bureau of Agriculture, carrying on the 

 routine work there of immunizing susceptible animals for serum 

 production, employed serum in several cases from animals that 

 had recently reacted. The results were as satisfactory as if 

 hyperimmune serum had been employed. Further, previous ex- 

 perience (6) had shown that the severity of the immunizing reac- 

 tion could be controlled by the amount of serum employed. 

 Thus, if the serum drawn in the field proved to be appreciably 

 low in protective power, the fault could readily be corrected. 



The work was inaugurated in Ilocos Norte Province on 

 carabaos belonging to the Calamba Sugar Estate, and intended 

 for shipment to their estate at Calamba, Laguna. When the 

 immunization was begun, there was available a supply of serum 

 from hyperimmunized animals only sufficient for the first three 



' One peso Philippine currency equals 50 cents United States currency. 



