STUDIES ON PNEUMONIC PLAGUE AND PLAGUE 

 IMMUNIZATION. 



IX. PROTECTIVE INOCULATION AGAINST PNEUMONIC 



PLAGUE. 



By Richard P. Strong and Oscar Teague. 

 {From the Biological Laboratory, Bureau of Science, Manila, P. I.) 



The epidemic of pneumonic plague, which raged in Manchuria 

 and northern China during the winter of the year 1910-1911 

 and which caused the death of over 50,000 people, brought 

 before us, among other problems, one of particular importance, 

 namely, that of protective inoculation against the disease. 



The Chinese Government spent over 100,000 dollars (Mexican) 

 on plague prophylactics during the epidemic, but, at its close, 

 their efficacy was' doubted. 



Inoculations with killed cultures were alone employed during 

 the epidemic. One hundred and thirty-two people were inocula- 

 ted at Harbin; 22 of these contracted plague, 13 after one in- 

 jection, 8 after two injections, and 1 after three injections. 

 Of the 8 who fell sick after two injections, 2 contracted plague 

 six days, 2 ten days, 2 fourteen days, 1 twelve, and 1 twenty- 

 seven days after the inoculation. Of the 13 who contracted 

 plague after one injection, 12 contracted plague after two weeks 

 and one after six days. 



Unfortunately, it was not possible to ascertain how many of 

 those inoculated were afterward exposed to pneumonic-plague 

 infection or how many, when exposed, protected themselves by 

 the wearing of masks. Dr. Wu ' reported to the Conference the 

 case of Mr. Liu, a medical student who worked with pneumonic- 

 plague patients for a whole month with no other precaution than 

 masking. On January 2 he was inoculated, and eight days 

 after he contracted pneumonic plague and died. He also reported 

 the case of Dr. Hsu who was inoculated on January 4 and con- 

 tracted pneumonic plague on January 22, and stated in addition 



' Report of the International Plague Conference held at Mukden, April, 

 1911. Manila (1912), 332. 



229 



