Xl] VACCINATION 1 89 



The inoculation of serum that had either been warmed, or 

 kept for eight days at 25° C, was found to confer a partial 

 immunity against yellow fever. All the subjects that had 

 received such injections, were subsequently inoculated with 

 a virulent strain of yellow fever, and in every case the resulting 

 attack was found to be extremely mild in character, shewing 

 that the serum had had an immunizing effect. 



During the course of an attack of yellow fever the presence 

 of antibodies in the blood of the patient may easily be demon- 

 strated. The serum of a patient taken on the eighth day of 

 an attack and injected into a non-immune person, completely 

 protected the latter against infection when subsequently inocu- 

 lated with virulent blood. The serum of a convalescent patient 

 is even more effective, and if injected into non-immune persons 

 will protect them against all attempts at infection for a period 

 of about 20 days. By the twenty-sixth day the immunity 

 begins to disappear but is still present, for the inoculation of 

 virulent blood only produces a slight attack of fever. 



Such immune serum may also be applied therapeutically, 

 and when injected into infected patients is said to diminish 

 the severity of the symptoms and hasten the recovery. 

 Unfortunately, all these methods are of little use, because 

 they require the presence of infected patients and conva- 

 lescents to furnish the necessary materials. 



REFERENCES. 



Boyce, R. (1911). Yellow Fever and its prevention. London : John 



Murray. 

 Clarac, A. and Simond, P. L. (191 2). Fievre Jaune, in Grail and 



Clarac's Traite Pratique de Pathologie Exotique. Paris. Vol. iii. 



pp. 21-176. 

 Finlay, C. (1883). Sur une nouvelle theorie de la fidvre jaune. Ref. 



Arch, de mid. nav. January, 1883. 

 Marchoux, E. (1910). Fievre Jaune, in Chantemesse and Mosny's 



Traitd d' Hygiene. Paris : Bailliere at fils. 

 Marchoux, Salimbeni and Simond (1903). La fievre jaune. Ann. Inst. 



Pasteur, vol. xvii. pp. 665-731. 

 Marchoux and Simond (1906) . £tudes sur la fievre jaune. Ibid. vol. xx. 



pp. 16, 104 and 161. 

 Reed, Carroll, Agramonte and Lazear (1900). Preliminary note on the 



Etiology of Yellow Fever. Phil. Med. Journ. Oct. 27. 



