184 MODERN BIOLOGIC THERAPEUSIS 



date stamped on the packages is not a reliable 

 guide for judging the activity of the vaccine, for 

 unless it is kept at a low temperature the virus 

 soon becomes inactive and will not produce 

 "takes." 



The lesson which these experiments teach is : 

 (1) Vaccine Virus should be kept in a refriger- 

 ator at a low temperature (about 40 F.) until 

 used. (2) The practitioner must not expect to 

 obtain "takes" if he uses Vaccine Virus that 

 has not been kept at low temperatures. 



TECHNIC OF VACCINATION 



Trivial and simple as the operation of vac- 

 cination appears, it is nevertheless a surgical 

 procedure and one requiring skill and special 

 knowledge to secure the most successful and sat- 

 isfactory results. Moreover, the after-care of 

 the wound is exceedingly important. 



The arm, at the insertion of the deltoid muscle, 

 is the safest site for vaccination, since it is more 

 easily kept clean than the leg, especially in in- 

 fants. In female children, if the leg be chosen 

 in order to avoid a scar upon the arm, special 

 care must be taken to keep the wound clean. 



The hands of the operator, the instrument 



