The clinical and immunologic efficacy of immunotherapy with modified ragweed extract (allergoid) for ragweed hay fever

Abstract

A double-blind study comparing formaldahyde modified ragweed allergen (allergoid) and placebo in the treatment of allergic rhinitis was carried out. Twenty ragweed-sensitive patients were studied, ten receiving 10,710 PNU of allergoid pre-seasonally and ten receiving placebo injections. Daily symptom score sheets were kept by each patient during August and September of 1983. A significant difference in average daily symptom scores (P = 0.01) between the two groups was noted. Significant differences were also observed in symptom scores for individual weeks during the ragweed season. Post-treatment allergen-specific IgG blocking antibody was significantly higher (P = 0.001) in the treatment group compared to pre-treatment levels and when compared to the control group (P = 0.01). No significant local or systemic reactions occurred. The results suggest that the dosage protocol used in this study is appropriate as an initial treatment schedule in clinical practice.