VACCINE-THERAPY 161 



for example, a streptococcal infection. It is quite possible 

 the failures recorded against Ferry's vaccine are due to 

 the fact that they have not been used soon enough in 

 the course of the disease. 



When secondary infection has taken place, the im- 

 munizer must ascertain in the first instance the exact 

 nature of the infection ; and, we believe, owing to the vari- 

 able nature of these infections, to obtain the maximum 

 benefit from sero-vaccine therapy, the immunizer must treat 

 each outbreak or case on its own merits, and for preference 

 making his own autogenous vaccines. 



In the past a variety of prophylactic and curative vaccines 

 have been put forward, some being highly spoken of, and 

 some condemned, each having its own exponents as well 

 as its opponents. 



In the hands of some the results have been good, while 

 with others they have been unsatisfactory. Why should 

 those diversities of results and opinions be ? 



Can they be due to any want of skill on the part of the 

 immunizer ? This is most improbable, for one capable prac- 

 titioner praises the vaccine, while another equally capable 

 condemns it. Is it not rather due to the unsuitability of 

 the vaccine to the particular outbreak ? and would we not 

 obtain a more even percentage of results if we used autog- 

 enous instead of stock vaccines ? Certainly, if we did, we 

 would be less empirical in our actions, and probably more 

 successful as immunizers. 



When a stock vaccine succeeds, we must reasonably con- 

 clude it possesses that specificity of action capable of 

 rousing the attacking forces against the specific bacterium 

 for which it is intended. 



The following are the principal sera and vaccines which 

 have been used : 



Lignieres cultivated many strains from a pasteurella he 

 isolated from distemper cases, and by a process of sub- 

 culture which he carried on for twelve months, he was able 

 to procure a strain possessing a mild degree of virulence. 



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