Using live attenuated influenza virus (LAIV) inoculation in human volunteers, this study will compare influenza-induced responses in non-smokers (NS), cigarette smokers (CS), e-cigarette smokers (EC), hookah smokers (HS), and Little Cigar smokers (LCS) in vivo. This will be done by analyzing nasal viral titers, antiviral defense responses, inflammatory mediator production, and markers of immune responses for LAIV-induced responses between the different groups of volunteers.