Safety and efficacy of two courses of OM-85 BV in the prevention of respiratory tract infections in children during 12 months

Background: Acute respiratory tract infections (ARTIs) are among the main causes of morbidity and mortality in children. The bacterial extract OM-85 BV (bronchovaxom) has shown protective effect for ARTIs on children. We report a double-blind, placebo-controlled, parallel, prospective clinical trial to assess the safety and efficacy of two courses of OM-85 BV in the prevention of ARTIs in susceptible children during 12 months. Methods: Fifty-four susceptible children from 1 to 12 years of age living in the metropolitan area of Chihuahua City were selected. They were randomized to receive either OM-85 BV or placebo (one capsule a day for 10 days a month for 3 consecutive months) at the beginning of the trial and 6 months later with the same schedule. Patients were followed up for 12 months, including the administration period. The trial began in July 1997 and ended in April 1999. Results: The number (mean +/- SD) of ARTIs was 5.04 +/- 1.99 (median, 5.0) in the OM-85 BV group vs 8.0 +/- 2.55 (median, 8.0) in the placebo group, with a mean difference of - 2.96 (95% confidence interval [CI], - -4.22 to - 1.7), The number of antibiotic courses was 2.46 +/- 2.08 (median, 1.5) in the treatment group vs 4.46 +/- 2.08 (median, 4.0) in the control group, a difference of - 2.0 (95% CI, - 3.14 to - 0.86). The total duration of ARTIs was 35.23 +/- 17.64 days (median, 30.5 days) in the OM-85 BV group vs 60.75 +/- 25.44 days (median, 55.0 days) in the placebo group, ie, a difference of - 25.52 days (95% CI, - 37.56 to - 13.47 days), p < 0.001 by Student's t test and Mann-Whitney U test for all the items. Four patients in the OM-85 BV group had five adverse events. Only one episode of skin rash was related to the medication intake. Six patients in the control group had six adverse events. Conclusions: OM-85 BV had a preventive effect on ARTI in the susceptible children for 12 months with an important reduction on the antibiotic requirements and the number of days of suffering ARTIs.