292 IMMUNOLOGY 



serum when administered in the preparalytic stage. The treat- 

 ment did not affect the incidence of paralysis nor the mortality 

 rate. An excellent review of the literature bearing upon the 

 serum treatment of poliomyelitis is given by Harmon (1934). 

 While convalescent serum is not an effective therapeutic agent 

 so far as the prevention of paralysis and death is concerned, it 

 was shown by Flexner to be of definite value when administered 

 prophylactically. 



There is no promise, at the present time, that active immuniza- 

 tion can be effected by means of a vaccine. This subject is dis- 

 cussed quite extensively by Zinsser, Enders and Fothergill, 1939, 

 p. 767. For those interested in the extensive research relative to 

 the virucidal property of normal, convalescent and immune sera 

 as well as the inactivating effect of anterior pituitary and other 

 substances of endocrine origin, a supplementary list of references 

 is appended. The student is also referred to an excellent brief 

 review of the subject of serum therapy in poliomyelitis given in 

 an editorial (1934). The editor calls attention to the fact that 

 while statistical evidence indicates that serum used therapeutically 

 may not prevent paralysis or death, nevertheless, symptomatic; 

 improvement is reported almost universally following the ad- 

 ministration of such sera. On the other hand Zinsser, Enders and 

 Fothergill (1939, p. 771) state that it is their opinion that the 

 intraspinal injection of serum may increase the edema of the cord, 

 and therefore be definitely harmful in some cases. 



Mumps. — Another virus disease which apparently can be pre- 

 vented by the injection of specific convalescent serum is epidemic 

 parotitis or mumps. It has an incubation period of about 18 

 days and is exceedingly contagious. Park (1928) reviews the 

 work of Hess (1915) and Regan (1925) and is inclined to at- 

 tribute definite ])rophylactic value to convalescent serum. 



Vaccinia and Variola. — There are a few reports in the litera- 

 ture such as those of Blackfan, Peterson and Conroy (1923), 

 Weech (1924) and Mitchell and Ravenel (1924) which indicate 

 that convalescent serum is of value in the prevention of variola. 

 Downs and Stookey (1932, 1933), working in this laboratory in- 

 vestigated the prophylactic and therapeutic value of specific im- 

 mune serum when administered to rabbits before and after in- 



