A Phase 2 Bridging Study to Assess the New Formulation of ETVAX

Inclusion Criteria: * Male or female aged 18-50 years, inclusive at the time of signing the informed consent. * Healthy constitution as established by medical history and physical examination. * Willing and able to give written informed consent for participation in the study. * Able to comply with study activities, as judged by the Investigator. * Female Participants: * Women of child-bearing potential (for definition see Section 9.3.6 in the protocol): * Have to agree to use an acceptable birth control method during participation in the investigation (see Section 9.3.6). * A negative pregnancy test (beta human chorionic gonadotropin dipstick test in urine) at Visit 2/Day 1 will be required. * Male Participants: * Have to agree to remain abstinent (refrain from heterosexual intercourse) or use a condom, and agreement to refrain from donating sperm, as defined in Section 9.3.6 Exclusion criteria * An acute or chronic medical condition that, in the opinion of the investigator/physician, would render ingestion of the investigational products unsafe or would interfere with the evaluation of responses. This includes, but is not limited to gastrointestinal diseases, and autoimmune diseases. * Current malignancy or history of malignancy during the last five years, based on anamnesis. * Gastroenteritis within two weeks prior to vaccination. * Regular use of laxatives, antacids or other agents that lower stomach acidity. * Any planned major surgery during the duration of the study. * After 10 minutes supine rest, any vital signs outside the following ranges: * Systolic BP \> 160 mm Hg * Diastolic BP \> 100 mm Hg * Heart rate \< 40 or \>85 beats per minute * Antibiotic therapy within two weeks prior to the vaccination. * Known Hepatitis A, B, C, and/or HIV infection. * Concomitant intake of immunomodulating drugs during the study period or less than 3 months prior to the first immunization, with the following exceptions: oral anti-histamines are not allowed during the study period or less than 3 weeks prior to the first immunization. Local anti-histamine treatment is allowed during the study period. * Any other significant medical conditions (e.g. poorly controlled psychiatric condition) judged by the Investigator to preclude entry. * Intends to receive any other vaccine during the study period, or within two weeks prior to trial vaccination. * Has previously received Dukoral or any type of ETEC or cholera vaccines. * Brought up in ETEC-endemic areas (e.g., urban and rural areas of Central and South America, Caribbean, most countries in Asia, Africa, etc.). * Has travelled to ETEC-endemic areas within the last 3 years OR spent \> two months in ETEC endemic areas during the last 10 years. * Intends to travel to ETEC endemic countries during the study period. * Known or suspected history of drug, chemical or alcohol abuse, as deemed by the investigator/physician. * History of severe allergy/hypersensitivity or ongoing allergy/hypersensitivity, as judged by the Investigator, or history of hypersensitivity to drugs with a similar chemical structure or class to ETVAX®. * Participation in any other clinical study that included drug treatment with the last administration within the past 3 months prior to administration of study treatment in this study. Patients consented and screened but not dosed in previous clinical studies are not excluded. * Concomitant participation in any other clinical study. * Females who are pregnant as determined by urine test at inclusion and prior to each vaccination. * Females who are nursing. * Unable to participate in all study visits. * Any condition or circumstance which would make the subject unsuitable for participation in the study in the opinion of the investigator/physician.