A Study to Assess Immunity to Specific Microbial Antigens in Healthy Smokers and Non-smokers and in Subjects With Stable COPD

Blood collection at Day 0 (all subjects) and at Month 6 (COPD subjects) for the analysis of serology, cell-mediated immune response.

Nasopharyngeal and oropharyngeal swabs collection at Day 0 (All subjects) and at exacerbation visits (COPD subjects).

Sputum collection at Day 0 and at exacerbation visits (COPD subjects)