Post Authorization Efficacy and Safety Study (PAES) to Confirm and Collect More Clinical Data of Buccalin® Tablets in the Prophylaxis of Recurrent Lower Respiratory Tract Infections (RLRTIs).

The goal of this clinical trial is to assess if BUCCALIN® works In the Prophylaxis of Recurrent Lower Respiratory Tract Infections (RLRTIS). It will also evaluate the safety of BUCCALIN®. The primary aim is to reduce the number of infection episodes in the treatment period (12 months) in the BUCCALIN® group versus the Placebo group. Patients diagnosed with RLRTIS will be screened for enrolment. Patients will be requested to provide informed consent before the start of the study related assessments. Eligible patients who meet the study inclusion and exclusion criteria will be randomized with a 1:1 ratio allocation to the 2 treatment groups. Researchers will compare BUCCALIN® (gastro-resistant tablets) to a placebo (gastro-resistant tablets containing only excipients) to treat RLRTIS. Patients who participate in the study will perform several study visits divided as reported below: * Run-in phase (12 months): patients will not receive any treatment. This phase is designed to increase adherence to the study and reduce loss to follow-up in the clinical trial. During this phase, patients should experience ≥ 2 episodes of RTIs to be eligible for the Treatment period. * Treatment period (12 months): patients will receive BUCCALIN® or Placebo treatment for 12 consecutive months (3 days per month, posology as per authorized SmPC). * Follow-up period (12 months): patients will not receive any treatment. This phase is designed to observe how patients respond to treatments.