A preliminary communication on the treatment of autumnal hay fever by vaccination with an aqueous extract of the pollen of ragweed

Dunbar was the first to attempt active immunization against hay fever by vaccination with aqueous pollen extract. He used 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 alleviating 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 prepared 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 suspension, 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 I C.C. of a one in five million solution to I C.C. of a one in five hundred thousand. The size of the initial dose, the increase in the amount at each injection, 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 symptoms corresponding very closely with the physical tests.