GENERAL CONSIDERATION OF FILTRABLE VIRUS 899 



studies by Wright 17 have shown that the intracutaneous injection 

 of 0.1 c.c. of the ordinary glycerinated virus diluted with one part 

 of sterile distilled water, resulted in " takes" when the ordinary 

 scarification methods were unsuccessful. He vaccinated 227 negro 

 soldiers in this way, and obtained over 70 per cent successful vac- 

 cinations when only slightly over 8 per cent were obtained on the 

 same series of cases previously, by the incision method. 



Sternberg, Kinyoun and others have demonstrated that within 

 two weeks after vaccination the blood serum of the vaccinated 

 patients will neutralize vaccine virus if allowed to stand with it 

 in a test tube overnight. 



That vaccination is of incalculable benefit to the human race is 

 no longer a question of opinion, and opposition to the practice is 

 explicable only on the basis of ignorance. Statistical compilations 

 upon this point are very numerous. It may suffice to select from 

 the voluminous literature a single example, taken from Jiirgensen, 

 which embodies the statistics of death from smallpox in Sweden, 

 during the periods immediately preceding and following the intro- 

 duction of vaccination* In that country the first vaccination was 

 done in 1801. By 1810 the practice was generally in use but not 

 enforced. In 1816 it was legally enforced. The years from 1774 

 to 1855 can thus be divided into three periods. 



1. Prevaccinal period, 1774-1801 (25 years). Deaths smallpox per 



million inhabitants 2,050 



2. Transitional period, 1801-1810 (9 years) 680 



3. Vaccination enforced, 1810-1855 (35 years) 169 



Prevaccinal period death rate 20.00 per mille. 

 Vaccinal period death rate 0.17 per mille. 



In considering the benefit of vaccination it must not be forgotten 

 that revaccination is quite as important as the first vaccination, 

 which confers immunity only for from seven to ten years. A child 

 should therefore be vaccinated soon after birth or at least before 

 the eighth month, and the process should be repeated about every 

 seven years thereafter. 



17 Wright, Jour. A. M. A. 71, 1918, 654. 



