Oral immunotherapy of chronic bronchitis: a double-blind placebo-controlled multicentre study

104 patients with chronic bronchitis were treated under randomized double-blind conditions with either Broncho-Vaxom (BV) or a placebo over a period of 6 consecutive months. The beneficial effect of BV was manifested by a statistically significant reduction in the duration of acute episodes and of fever (p less than 0.001) with respect to the placebo group. The consumption of antibiotics dropped significantly in the BV group (p less than 0.05) but not in the placebo group. The serum IgA levels increased in the BV group and the difference with the placebo group was statistically significant (p less than 0.05) from the 3rd month onwards. In the patients with bronchitic exacerbations during the trial, T-lymphocyte counts increased steadily under BV therapy until 3 months after the exacerbation (p less than 0.05), but not under the placebo. BV was generally well tolerated with the exception of 1 patient who reported nausea and upper abdominal pain. In their assessment of the overall therapeutic effect, the physician judged BV to be significantly superior (p less than 0.001) to the placebo as regards both the curative and prophylactic efficacy.