Abstract
Perennial hyposensitization with a partially purified timothy extract resulted in a statistically significantly higher degree of clinical protection than treatment with the 2 timothy major allergens (no. 19 and 25) and protected better in the 2nd than during the 1st grass pollen season. The extracts were standardized biologically and absorbed to Al(OH)3 for administration. The therapy had a more beneficial influence on sneezing than on rhinorrhea and blockage of nasal airways, and an excellent effect on grass pollen asthma was obtained with the partially purified timothy extract. Associated birch pollen allergy was not influenced by hyposensitization with grass pollen.