A Study to Assess the Efficacy and Safety of Daily OM-85 in Young Children With Recurrent Wheezing

Inclusion Criteria: Subjects who meet all the following criteria will be included in the study: Children of either gender, aged between 6 and 72 months (5 years inclusive). Children with recurrent wheezing: For ICS/LTRA naïve patients or intermittent users (patients using ICS treatment only during an upper RTI to prevent WE): ≥2 WEs including at least 1 severe episode (i.e., treated with OCS OR having triggered an ED visit/hospitalization), OR ≥3 WEs including at least one that triggered an unscheduled physician visit, in the 12 months prior to enrollment. For ICS/LTRA daily users: ≥1 severe WE (i.e., treated with OCS OR having triggered an ED visit/hospitalization) OR ≥2 WEs including at least one that triggered an unscheduled physician visit, as reported by parents or LAR of subject (i.e., guardians), in the 12 months prior to enrollment, while being on their daily controller therapy. Up-to-date vaccination status as per applicable State Vaccination Requirements for school/day-care entry. Parents or LAR have provided the appropriate written informed consent. Written informed consent must be provided before any study-specific procedures are performed including screening procedures. Note: If a subject is experiencing respiratory symptoms at time of screening, he/she could only be randomized once symptoms have resolved for at least one week. Exclusion Criteria: Known anatomic alterations of the respiratory tract. Wheezing documented to be caused by gastroesophageal reflux. Other known chronic respiratory diseases (e.g., tuberculosis or cystic fibrosis). Any known autoimmune disease. Known human immunodeficiency virus (HIV) infection or any known type of congenital or iatrogenic immune deficiency (including immunoglobulin (Ig) A deficiency). Known acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal function abnormalities. Children born prematurely i.e., before 34 weeks of gestational age. Children with an abnormally low or high weight for their age and height, if this would not allow safe completion of the clinical study in the opinion of the investigator. Any known neoplasia or malignancy. Treatment with the following medications: Systemic (intravenous or intramuscular) or OCS (e.g., oral prednisolone) within 4 weeks before study enrollment. Previous and/or concomitant immunosuppressants, immunostimulants, or gamma globulins within 6 months before study enrollment. Any major surgery within the last 3 months prior to study enrollment. Known allergy or previous intolerance to investigational drug. Any other clinical conditions, which in the opinion of the Investigator, would not allow safe completion of the clinical study. Other household members have previously been randomized in this clinical study. Inability to comply with the study requested visit schedule (e.g., expected relocation within 12 months of the screening for the study). Currently enrolled in or has completed any other investigational device or drug study <30 days prior to screening or receiving other investigational agent(s). Note: Subjects with past, present, or at risk of COVID-19 should not be excluded from the study.