Inclusion Criteria:  Male or female between the ages of 18 - 49 years, inclusive Able to give written informed consent Healthy, as determined by the principal investigator (PI) or PI in consultation with the research monitor and Sponsor Healthy = No clinically significant health concerns or medical illness, as determined by medical history, physical examination, vital signs, electrocardiogram (ECG), and clinical laboratories (complete blood count (CBC), chemistry and urinalysis) Comprehension of the study requirements with ability and willingness to complete all assessments and comply with confinement period post viral challenge, and all scheduled visits and contacts Confirmed blood type (A or O) Demonstrated to be H type-1 antigen secretor positive (by saliva test) Body mass index between 17 and 35 kg/m2, inclusive, at Screening  Female participants must have a negative pregnancy test at pre-vaccination and pre-challenge and fulfill one of the following Criteria:  At least one year post-menopausal; Surgically sterile; Use of oral, implantable, transdermal or injectable contraceptives for 30 days prior to immunization and until 60 days after challenge;  i. A reliable form of contraception must be approved by the Investigator (eg, double barrier method, Depo-Provera, intrauterine device, Norplant, oral contraceptives, contraceptive patches) d. Not be sexually active (abstinent) or in a same sex relationship (must be discussed with site staff and documented)  Male subjects must agree not to father a child or donate sperm, as well as to use contraception/barrier (a male condom) or be abstinent from heterosexual intercourse, from vaccination through the active period (Day 57)  Exclusion Criteria:  Administration/use of any investigational drug or device 30 days prior to vaccination through the active period (Day 57) Administration of any licensed vaccine within 30 days prior to vaccination or planned use of the above stated during the active period (through Day 57) Presence of a significant medical condition, which, in the opinion of the investigator, precludes participation in the study. Significant medical condition = for example, psychiatric conditions, or gastrointestinal disease, such as peptic ulcer, symptoms or evidence of active gastritis or gastroesophageal reflux disease, inflammatory bowel disease, alcohol or illicit drug abuse/dependency, or other laboratory abnormalities Laboratory values outside the range of normal for platelet counts and the following coagulation tests: prothromibin time test (PT/INR), activated partial thromboplastine time test (aPTT) and fibrinogen  Any of the following history or conditions that may lead to higher risk of clotting events and/or thrombocytopenia:  Family or personal history of bleeding or thrombosis History of heparin-related thrombotic events, and/or receiving heparin treatments History of autoimmune or inflammatory disease  Presence of any of the following conditions known to increase risk of thrombosis within 6 months prior to screening:  Recent surgery other than removal/biopsy of cutaneous lesions Immobility (confined to bed or wheelchair for 3 or more successive days) Head trauma with loss of consciousness or documented brain injury Receipt of anticoagulants for prophylaxis of thrombosis Recent clinically significant infection  Any one of the following ECG findings within 45 days prior to vaccination:  Exclusionary ECG findings:  QTc F (interval duration > 450 msec (male) or > 470 msec (female) QRS interval greater than 120 msec PR interval greater than 220 msec Clinically significant ST-T wave changes or pathologic Q waves History of cancer or cancer treatment within past 3 years (excluding basal cell or squamous cell carcinomas) Presence of immunosuppression or medical condition possibly associated with impaired immune responsiveness, including diabetes mellitus or angioedema Donation or use of blood or blood products within 30 days prior to vaccination through the active period (Day 57) Diagnosed bleeding disorder or significant bruising or bleeding difficulties that could make blood draws problematic Any condition that resulted in the absence or removal of the spleen Evidence of confirmed infection with human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV) with confirmatory assays Abnormal stool pattern (fewer than 3 bowel movements per week or more than 3 per day)  History of irritable bowel disease or inflammatory digestive or gastrointestinal condition that could affect the distribution / safety evaluation of an orally administered vaccine targeting the mucosa of the small intestine.  Such conditions may include but are not limited to:  Esophageal Motility Disorder Malignancy Malabsorption (e.g. Celiac disease, gluten intolerance) Pancreaticobiliary disorders Irritable bowel syndrome Inflammatory Bowel Disease Surgical Resection with the exception of appendectomy or a minor resection that is deemed acceptable by investigator and sponsor Gastroesophageal reflux disease (GERD) Hiatal Hernia Peptic Ulcer (History of cholecystectomy is not exclusionary) Use of proton pump inhibitors, H2 blockers or antacids within 7 days prior to vaccination through the active period (Day 57) Use of antibiotics within 30 days prior to vaccination through the active period (Day 57) Note: use of a brief (≤ 10 days) course of oral or topical antibiotic for minor upper respiratory infection (URI), urinary tract infection (UTI), dental work, or skin infection allowed within the screening period, but must be completed 7 days prior to first vaccination Use of medication known to affect the immune function (e.g. systemic corticosteroids and others) within 14 days prior to vaccination through the active period (Day 57) Regular use of nonsteroidal anti-inflammatory drugs within 7 days prior to vaccination through the active period (Day 57) Use of over-the-counter probiotics or antidiarrheals within 7 days prior to vaccination through the active period (Day 57) Evidence of recent (within 2 months of vaccination) or of current nonbacterial gastroenteritis suggestive of NV infection [vomiting or unformed or watery stools (> 2 during a 24-hour period)] Any gastroenteritis within the past 2 weeks prior to vaccination Acute disease within 72 hours prior to vaccination, defined as the presence of a moderate or severe illness with or without fever (as determined by the Investigator through medical history and physical examination). (Assessment may be repeated during screening period) Presence of a fever ≥ 38ºC measured orally at baseline History if hematochezia (blood in stool) or melena (black stool) Any significant hospitalization within the last year which in the opinion of the investigator or sponsor could interfere with study participation History of serious reactions to any vaccination such as anaphylaxis, respiratory problems, Guillain-Barre syndrome, hives or abdominal pain History of a hypersensitivity or allergic reaction to any component of the investigational vaccine or placebo, including but not limited to fish gelatin. Subjects with known fish allergies should be excluded. History of drug, alcohol or chemical abuse within 1 year prior to vaccination Positive test for drugs of abuse or alcohol at screening, vaccination baseline and pre-challenge (except for previous marijuana use; concurrent or ongoing use of marijuana during the active study period). Consistent/habitual smoking within 2 months prior to vaccination (defined as smoking ≥ 1 pack of cigarettes a day). Smoking is not permitted during the inpatient stay  Other conditions, in the clinical judgment of the investigator, that would jeopardize the safety or rights of a subject or interfere with the evaluation of the study  Social/Occupational:  Living with or having daily contact with children < 5 years old or women known to be pregnant or nursing; this includes significant contact at home, school, day-care, or equivalent facilities Living with or having daily contact with elderly persons > 70 years of age or infirmed, diapered individuals, persons with disabilities or incontinence; this includes at work or visits to nursing homes and day-care or equivalent facilities Employment in the food service industry such as restaurant or cafeteria facilities; specifically, this includes persons whose employment requires food handling and processing in the 4 weeks following viral challenge Health-care workers with patient contact expected in the 4 weeks following viral challenge Expected contact, via employment or at home, with immunocompromised persons in the 4 weeks following viral challenge. Immunocompromised persons = HIV-positive, receiving immunosuppressive medications such as oral steroids, anti-neoplastic agents Presence of household members who have received the Ad4 or Ad7 vaccines within 2 months prior to vaccination Employment as an airline flight attendant or cruise ship crew, scheduled to work in the 4 weeks following challenge Persons planning to live in a confined environment (eg, a cruise, camp, etc.) in the 4 weeks following viral challenge