i2 4 INFECTION AND IMMUNITY 



accomplished in the countries where the disease has 

 its permanent habitat, there is every reason to believe 

 that its complete extinction would soon be effected. 



The prevention of cholera by " protective inocula- 

 tions " has been tested on a large scale in Spain, 

 during the epidemic of 1885, a d more recently in 

 India, by the method of Haffkine. 



Unfortunately the evidence relating to the value 

 of these protective inoculations is not very satisfac- 

 tory. The evidence, however, is in favour of the 

 view that a partial and temporary immunity may be 

 conferred by the subcutaneous injection of cultures 

 of the cholera germ. We should not expect such 

 inoculations to confer an absolute immunity, inas- 

 much as this does not result from an attack of the 

 disease. That repeated attacks may occur in the 

 same individual is well established, and this may hap- 

 pen during a single epidemic, as was observed in the 

 last Hamburg epidemic. 



That the inoculated are not exempt from attack 

 is shown by Haffkine's statistics with reference to in- 

 oculations made by him in India (1895). Five hun- 

 dred inoculated individuals gave a mortality of 19, or 

 3.8 percent., while among 1735 non-inoculated, under 

 similar conditions, the mortality was 6.5 per cent. In 

 our opinion inoculation as a method of prevention 

 should not be employed on a large scale in anticipa- 



