Screening visit (2-4 weeks prior to Day 0): Obtain informed consent, history (including smoke exposure questionnaire), physical examination, vital signs (VS), blood draw (for anti-influenza antibody titer, HIV and T cell stimulation with flu antigen), urine (for cotinine), nasal lavage (NL, for differential cell count, viral culture and antigen detection, cytokine panel), nasal epithelial lining fluid (ELF, collected with filter paper for cytokine analysis), nasal epithelial biopsy (NB) #1, pregnancy test for females of child bearing potential. In addition, smokers will undergo spirometry.