Reactogenicity, Safety and Immunogenicity of a LAIV А/17/Hong Kong/2017/75108 H7N9 Influenza Vaccine

Inclusion Criteria: * Legal male or female adult 18 through 49 years of age at the enrollment visit. * Literate and willing to provide written informed consent. * A signed informed consent. * Free of obvious health problems, as established by the medical history and screening evaluations, including physical examination. * Capable and willing to complete diary cards and willing to return for all follow-up visits * Willing to comply with the rules of the isolation unit (including willing and able to take oseltamivir influenza antiviral medication, should that be recommended by a study physician). * For females, willing to take reliable birth control measures through day 56. Exclusion Criteria: * Participation in another clinical trial involving any therapy within the previous three months or planned enrollment in such a trial during the period of this study. * Receipt of any non-study vaccine within four weeks prior to enrollment or refusal to postpone receipt of such vaccines until four weeks after study completion. * Practice of nasal irrigation on a regular basis within the past six months or has engaged in nasal irrigation within two weeks prior to enrollment. * Recent history of frequent nose bleeds (more than 5 within the past year). * Clinically relevant abnormal paranasal anatomy. * Recent history (within the past month) of rhino or sinus surgery, or surgery for any traumatic injury of the nose. * Current or recent (within two weeks of enrollment) acute respiratory i…