RecruitingPhase 4Biological interventionWoodsmoke Exposure, Influenza Infection, and Nasal ImmunityThis study will investigate the effects of woodsmoke (WS) exposure on human nasal mucosal immune responses to viral infection. The study tests the hypotheses that WS exposure modifies biomarkers of nasal mucosal immune function, increases in Live Attenuated Influenza Virus (LAIV) -induced nasal symptoms, and reduces mucosal antibody production.