OM 85 to Prevent Respiratory Infections in Older At Risk Patients

Inclusion Criteria: * Age 75 years or older * At least 2 RTIs in the year prior to enrollment * Patients must have been residing in nursing homes for at least 6 months and have an estimated length of stay in nursing homes of at least 6 months by their treating physician. * Signed informed consent. If participants are unable to provide informed consent due to cognitive impairment, consent will be provided by a legally recognized representative or trustee of the patient (pursuant to Article 4 of Law No. 219 of December 22, 2017). * Have a life expectancy of at least one year in the judgment of their treating physician. Exclusion Criteria: * Patients with known allergy or previous intolerance to any component (including the excipient) of the study drug * Patients with active neoplasia and prognosis of less than one year * Patients with previous organ transplantation * Patients treated with prohibited drugs (see Table 1) in the 3 months prior to the start of the study * Patients who have taken bacterial lysates in the 6 months prior to enrollment or are currently using them * Patients regularly treated with oral corticosteroids * Patients unable to follow instructions and unreliable patients (including patients with alcoholism or patients unwilling to give informed consent or comply with protocol requirements) * Patients with any other clinical condition that, in the opinion of the investigator, would not allow completion of the protocol and safe administration of the study drugs