Acute wheezing illnesses are the most common reason that preschool aged children are admitted to hospital in
Australia and New Zealand. Current strategies to prevent these admissions are ineffective and new approaches
are required. OM-85 is an orally administered bacterial lysate that stimulates anti-viral immune responses and
reduces excessive airway inflammation associated with wheezing episodes. OM-85 has been shown to prevent
recurrent respiratory tract infections and may also prevent wheezing illnesses in infants and children.
However, data regarding the efficacy of OM-85 in preventing wheezing illnesses are limited and larger studies
are required.
The Assessing the Reduction of Recurrent admissions using OM-85 for the treatment of preschool Wheeze
(ARROW) trial is a randomised, double-blinded, placebo-controlled trial that will determine the efficacy of OM 85 for prevention of hospital admissions in children with recurrent preschool wheeze. Participants will take a
3.5 mg capsule of OM-85 or placebo daily for the first 10 days of every month, for 12 months. The primary
outcome is whether the child has a hospital admission due to an acute wheezing illness during the 12-month
treatment period. Secondary outcomes include the frequency and severity of wheeze episodes, and the cost effectiveness of the intervention.