THE CUTANEOUS VACCINE FOR FOWL POX 



By Norman J. Pyle, Assistant Research Professor of Avian Pathology, 



Cutaneous vaccination against fowl pox' (chicken pox, contagions epithel- 

 ioma) has been given considerable attention during the last few years in this 

 country and abroad. The work of De Blieck and Van Heelsbergen (1) is 

 widely known and needs little reference here. Their vaccine, known as 

 "Antidiplitherin", is described as "a thoroughly living vaccination material". 

 Reports of similar investigations by Johnson (2), Pyle (3), Edgington and 

 Broerman (4), and Saiwyer (5) have been published. These writers concur 

 in the conclusion that poultry can be fully protected against fowl pox by 

 the administration of an unattenuated virus suspension or cutaneous vaccine 

 to the scarified skin or denuded feather follicles. 



The early work of the writer (3) dealt largely with the type of immunity 

 that is- conferred against fowl pox. A serological study of fowls which were 

 immune to the disease, showed a low degree of specific antibody concentra- 

 tion in their sera. Attempts to produce a passive immimity were not success- 

 ful. An efficient cutaneous vaccine v/as developed and a tentative method of 

 standardizing it was suggested. Birds wiiich were completely immune to 

 both the natural infection and the experimental infection following cutane- 

 ous vaccination, were found to have no specific antibodies in their sera. 

 Therefore, it was concluded that a cutaneous immunity was the chief pro- 

 tecting force against fowl pox. The work of Verge (6) is a practical dem- 

 onstration of this type of immunity in relation to fowl pox, while that of 

 Besredka (7) goes deeply into the theoretical explanation and application of 

 the phenomenon. 



The work herein reported considers additional inform.ation on the use 

 and efficiency of this vaccine, its reaction on birds of various ages, its cura- 

 tive as well as its preventive effect, a modification in its virus content, the 

 duration of immunity which it produces, and the action of the glycerol con- 

 tent of the diluent on the virus in the vaccine. 



The Cutaneous Vaccine and Its Administration 



The cutaneous vaccine as described and standardized by the writer (3), 

 with the exception of one modification which will be mentioned later, was 



1 Fowl pox is manifested by wartlike scabs on the unfeathered portions of the 

 head and the accumulation of cheesy material, pseudo-membranes, or "cankers" on the 

 membranes of the mouth, larynx, and in the cleft palate. The latter group of symp- 

 toms is characteristic of the internal form of fowl pox or avian diphtheria ("canker"). 

 The two forms of the disease are due to the same cause, a filtrable virus. When there 

 is a muco-purulent discharge from the eyes and nose, or these organs and the infra- 

 orbital sinuses are distended with cheesy exudates, the disturbance is known as roup. 

 Roup may occur in Massachusetts concurrently with fowl pox or it may be seen alone. 

 It is generally accepted that its specific cause is as yet unknown, but there is evidence 

 to the effect that the filtrable virus of fowl pox is at least implicated. The eyes may 

 be involved in avian diphtheria, and if they are, it is difficult to differentiate it from 

 roup. 



