Patient description: The patient is a 35-year-old woman with myasthenia gravis, class IIa. She complains of diplopia and fatigue and weakness that affects mainly her upper limbs. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She takes pyridostigmine 60 mg three times a day. But she still has some symptoms that interfere with her job. She is a research coordinator and has 3 children. Her 70-year-old father has hypertension. She does not smoke or use illicit drugs. She drinks alcohol occasionally at social events. Her physical exam and lab studies were not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 18.0-85.0,  Gastroenteritis Participants must meet all of the listed below: 1. Signed written informed consent. 2. Age Cohort A: 18-49 years, inclusive Cohort B: 50-64 years, inclusive Cohort C: 65-85 years, inclusive Cohort D: 18-49 years, inclusive 3. Health Status Cohort A and D: In good health as determined by a screening evaluation that includes vital signs, medical history, and physical exam within 45 days before administration of IM Norovirus Bivalent VLP Vaccine or control Cohorts B and C: In good health as determined by a screening evaluation that includes vital signs, medical history, and physical exam within 45 days before administration of IM Norovirus Bivalent VLP Vaccine or control. Any existing medical diagnoses or conditions must be stable based on medical history and targeted physical examination. A stable medical condition is defined as: (A) Clinically acceptable health outcomes for the specific condition over the prior 6 months and (B) No change in prescription medication(s), dose, or frequency over the prior 3 months. Acceptable changes in medications are: a change of health care provider or insurance company or that is made for financial reasons as long as the medications are in the same class and/or a change due to improvement in a disease outcome. 4. Expressed interest and availability to fulfill the study requirements. 5. Female participants must be of non-childbearing potential (surgically sterile or post-menopausal for greater than or equal to [>=] 12 months), or if of childbearing potential (as determined by the investigator) must be practicing abstinence or using an effective licensed method of birth control (example oral contraceptives; diaphragm or condom in combination with contraceptive jelly, cream, or foam; intrauterine contraceptive device, or Depo-Provera; skin patch; vaginal ring or cervical cap) for 30 days prior to vaccination and must agree to continue such precautions for at least 60 days after the last vaccination. A woman is eligible if she is monogamous with a male who has had a vasectomy. Male participants must agree not to father a child for at least 60 days after the last vaccination and to practice abstinence or use an effective method of birth control as noted above. 6. Agrees not to participate in another clinical trial with an investigational product for the entire duration of the study one year after the last study dose that is 393 days. 7. Agrees to storage of unused clinical specimens for an indefinite period of time for future norovirus research or research on other gastrointestinal pathogens  Participants who meet any of the at baseline will be excluded from study participation. The are: 1. History of any of the following medical illnesses Diabetes Cancer (malignancy other than resolved/excised skin lesion) Heart disease (hospitalization for a heart attack, arrhythmia, or syncope) Unconsciousness (other than a single brief "concussion") Seizures (other than febrile seizures as a child less than [<] 5 years old) Recurrent infections (more than 3 hospitalizations for invasive bacterial infections such as pneumonia or meningitis) Any condition associated with immunodeficiency or participants taking immunosuppressant medication