Patient description: A 34 year old man comes to the clinic complaining of dizziness and severe diarrhea since yesterday. He has returned from an international trip few days ago and was living in a camp in Sudan for a month. He developed abdominal pain followed by bloating and nausea as well as loose bowel movements. Soon he was having profuse watery diarrhea without odor. The stool is watery and white but the patient has no fever. Blood pressure is 95/62 lying down and drops to 75/40 standing. The skin turgor has reduced. HR is 110 and he looks ill with dry mucosa. V. cholerae was seen in dark-field microscopy of a fresh stool specimen. The lab study is as bellow: Sodium 137 meq/L Potassium 2 meq/L Chloride 94meq/L CO2 15 meq/L Fecal leukocytes None seen Fecal occult blood Negative

Clinical trial eligibility criteria: eligible ages (years): 0.192-0.917,  Cholera Diarrhea Vibrio Infections Infants 10 weeks to 6 months of age at Day 0 Healthy infants aged from birth to 2 months who have not received OPV1, DTP1 or HepB2 will be recruited in Kolkata, North 24 Parganas, and South 24 Parganas All subjects must satisfy the following at study entry: 1. Male or female infants aged from birth to 2 months who the investigator believes will comply with the requirements of the protocol (i.e., available for follow-up visits and specimen collection) 2. Written informed consent obtained from their parents/guardians 3. Healthy subjects as determined by Medical history Physical examination Clinical judgment of the investigator Infants 9 months to less than 12 months Healthy infants aged from 9 months to less than 12 months who have not received measles vaccine will be recruited in Kolkata, North 24 Parganas, and South 24 Parganas All subjects must satisfy the following at study entry: 1. Male or female infants aged from 9 months to less than 12 months who the investigator believes will comply with the requirements of the protocol (i.e., available for follow-up visits and specimen collection) 2. Written informed consent obtained from their parents/guardians 3. Healthy subjects as determined by Medical history Physical examination   Infants 10 weeks to 6 months of age at Day 0: 1. Ongoing serious chronic disease 2. Immunocompromising condition or therapy 3. Diarrhea (having more frequent watery stools than usual within a 24 hour period) 6 weeks prior to enrollment 4. Intake of any anti-diarrheal medicine in the past week 5. Irritability, loss of appetite, general ill-feeling or vomiting in the past 24 hours 6. Acute disease one week prior to enrollment, with or without fever. Temperature =>38C (oral) or axillary temperature =>37.5C warrants deferral of the vaccination pending recovery of the subject 7. Receipt of antibiotics in past 14 days 8. Receipt of killed oral cholera vaccine 9. Receipt of live or killed enteric vaccine in 2 months 10. Receipt of DTwP1, OPV1 or Hepatitis B2 vaccines 11. One or two episodes of diarrhea lasting for more than 2 weeks in the past 2 months 12. One or two episodes of abdominal pain lasting for more than 2 weeks in the past 2 months 13. Z-score of < -2 on the weight for age WHO Child Growth Standards  Infants 9 months to less than 12 months: 1. Ongoing serious chronic disease 2. Immunocompromising condition or therapy 3. Diarrhea (3 or more loose/watery stools within a 24 hour period) 6 weeks prior to enrollment 4. Intake of any anti-diarrheal medicine in the past week 5. Abdominal pain/cramps, loss of appetite, general ill-feeling or vomiting in the past 24 hours 6. Acute disease one week prior to enrollment, with or without fever. Temperature =>38C (oral) or axillary temperature =>37.5C warrants deferral of the vaccination pending recovery of the subject 7. Receipt of antibiotics in past 14 days 8. Receipt of killed oral cholera vaccine 9. Receipt of live or killed enteric vaccine in last 4 weeks 10. Receipt of measles-containing vaccine (MCV) 11. One or two episodes of diarrhea lasting for more than 2 weeks in the past 6 months 12. One or two episodes of abdominal pain lasting for more than 2 weeks in the past 6 months 13. Disease episode potentially related to measles 14. receipt of blood, blood products or a parenteral immunoglobulin preparation in past 3 months 15. History of anaphylaxis, any serious vaccine reaction, allergy to eggs, egg products or to any measles vaccine component 16. Any condition which in the opinion of the investigator might interfere with the evaluation of the study objectives 17. Z-score of < -2 on the weight for age WHO Child Growth Standards