Protecting Preterm Infants From Respiratory Tract Infections and Wheeze by Using Bacterial Lysates.

This is a randomised placebo-controlled trial including 500 otherwise healthy moderate-late preterm infants. Participants will receive bacterial lysate (OM-85/Broncho-Vaxom, 3,5mg) or placebo powder for ten days each month, from 6-10 weeks after birth until 12 months after birth. At 12 months, parents of participants are asked to join in Protea-2. If they do, participants in the treatment arm of year 1 are randomised again over placebo and OM-85 and treated until the age of 24 months. Clinical data will be continuously collected by e-Health and 3 (possibly digital) study visits; with optional biological sampling and lung function at baseline, 6 and 12 months. And in case of participation in Protea-2 also at 24 months. Main study parameters are doctor diagnosed lower RTI and wheezing episodes in the first year of life. Biological sampling will allow investigation of immune maturation, as well as microbiome development in the respiratory tract and gut. Also, biomarkers for risk-group selection and/or treatment success will be examined.