• Provide written informed consent prior to initiation of any study procedures.

• Are able to understand and comply with all planned study procedures.

• Healthy males and non-pregnant, non-breast-feeding females aged ≥18 and ≤49 years of age inclusive at enrollment.

• Women of childbearing potential must be practicing abstinence or using an acceptable method of birth control for at least 30 days prior to enrollment through the duration of the trial. Male subjects must agree not to father a child for the duration of the trial.

• Women of childbearing potential must have a negative serum or urine pregnancy test at screening and negative urine pregnancy test within 24 hours prior to challenge.

• Are in good general health, as determined by the study investigator within 30 days of challenge and do not have any of the following conditions:

‣ Chronic pulmonary disease (e.g., asthma or reactive airway disease, emphysema)

⁃ Chronic cardiovascular disease (e.g., cardiomyopathy, congestive heart failure, cardiac surgery, ischemic heart disease, known anatomic defects)

⁃ Chronic medical conditions requiring close medical follow-up or hospitalization during the past 5 years (e.g., diabetes mellitus, renal dysfunction, hemoglobinopathies)

⁃ Immunosuppression or ongoing malignancy or history of malignancy (excluding nonmelanotic skin cancer in remission without treatment for more than 5 years)

⁃ Neurological and neurodevelopmental conditions (e.g., cerebral palsy, epilepsy, stroke, seizures)

⁃ History of postinfectious or postvaccine neurological sequelae

⁃ Autoimmune, inflammatory, vasculitic or rheumatic disease, including but not limited to systemic lupus erythematosus, polymyalgia rheumatica, rheumatoid arthritis or scleroderma

• Demonstrate knowledge and comprehension of the study by scoring ≥70% on a quiz of the study protocol and policies.

• Agrees to not use cigarettes, e-cigarettes, marijuana, or other tobacco products during the quarantine period.

• Agrees to not use prescription or over-the-counter medications that could impact influenza challenge efficacy or symptoms (including oseltamivir, zanamivir, peramivir, baloxavir marboxil, amantadine and rimantadine, aspirin, intranasal steroids, acetaminophen, decongestants, antihistamines, and other NSAIDs), within 14 days prior to quarantine and through the quarantine period, unless approved by the investigator.