Vaccination for Autumnal Hay Fever. 71 



too large a dose (about ten thousand times that which we have found 

 most satisfactory), and the patient on whom he tried the experiment 

 experienced such a violent anaphylactic shock that he decided to 

 abandon direct vaccination, and subsequently resorted to passive 

 procedures. Noon and Freeman succeeded in considerably alle- 

 viating the condition of sufferers from European or spring hay 

 fever by injecting small doses of timothy pollen extract. 



So far as we are aware no previous attempts have been made to 

 immunize against American autumnal hay fever by vaccination. 

 The extracts which we have employed for this purpose were pre- 

 pared from the pollen of ragweed by one of the two following 

 procedures: (1) That previously employed by Dunbar consisting 

 of repeated freezing and thawing in a 5 per cent, aqueous suspen- 

 sion, and (2) an original method, which consists of precipitating 

 the pollen with acetone and extracting with water. 



A series of eight cases were vaccinated last summer, using 

 doses ranging for the most part from 1 c.c. of a one in five 

 million solution to 1 c.c. of a one in five hundred thousand. The 

 size of the initial dose, the increase in the amount at each injec- 

 tion, the number of doses administered (ranging from three to 

 twelve), and the time intervals (ranging from two to six days) 

 were regulated by making frequent ophthalmic, cutaneous and 

 blood tests and noting the measure of immunity indicated by 

 these tests and the general condition of the patient. All the 

 cases treated experienced a marked alleviation of general symp- 

 toms corresponding very closely with the physical tests. In the 

 following table are recorded the initial resistance, maximum 

 resistance, and resistance five months after completion of treat- 

 ment exhibited by a series of cases. The figures represent the 

 number of units of pollen toxin required to produce a definite 

 ophthalmic reaction, one unit being the soluble constituents of 

 one twenty-millionth of a gram of pollen. The figures included 



Resistance Classified Under Treatment. 





Initial. 



Maximum. 



Five Months After 





Treatment. 



Dr. C 



2 



2.000 (40,000) 



10 



W 



40 



2,000 (20,000) 



20 



Dr. Ch 



20 



1,000 



10 



Dr. P 



40 



2,000 



10 



Mrs. W 



2 



1,000 





