OM-85 in the prevention of respiratory infections: State-of-the-art and future perspectives in clinical practice.

Respiratory infections (RI) significantly burden patients, their families, and society. Respiratory infection recurrence (RRI) usually depends on a defect of the immune response, which can be more or less transient and/or selective. In particular, children, older people, heavy smokers, and patients with chronic diseases, characterized by an inadequate immune response, may be at risk of developing RRI. In this context, OM- 85 could represent a valuable option in the management of RRI. OM-85 is a bacterial lysate containing the extracts of some common pathogens, including , , , , , , and . Methodologically rigorous studies have documented the mechanism of action, efficacy, and safety of OM-85. OM-85 enhances the natural and acquired immune response through multifaceted mechanisms. Substantial evidence has shown that OM-85 can prevent respiratory infections, reduce the number of COPD exacerbations, and shorten the disease duration at home or in hospital. OM-85 can enhance the effectiveness of the 'flu vaccination without affecting the vaccine tolerability. The preventive use of OM-85 can reduce the use of antibiotics, contributing to contrast antibiotic resistance and saving the high cost of chronic respiratory diseases. Further studies should define the ideal candidate to OM-85 treatment.