Section to complete information about the inclusion and exclusion criteria for participant selection, including age and gender.
Inclusion criteria:
1-Healthy man between 18 to 40 years of age. 2-Free from obvious health problems as established by medical history, clinical examination, laboratory tests and psychometric tests before entering into the study. 3-Written informed consent obtained from the subjects.
Exclusion criteria:
1-Previous history of immunodeficiency. 2-Cardiovascular, respiratory, renal, hematological, hepatic, gastrointestinal, neurological, endocrine, and psychiatric diseases or reticuloendothelial system disorders detected during the clinical examination or by laboratory tests. 3-Allergy to tetracyclines. 4-Previous cholera vaccination or challenge with V. cholera virulent strain (applicable only to the stage I). 5-Administration of immunoglobulins and/or antibiotics within 30 days preceding the treatment. 6-Positive serological test for human HIV-1-2 virus antibodies. 7-Positive serological test for human hepatitis B surface antigen, or hepatitis A and C antibodies. 8-Stool cultures positive for an enteric pathogen. 9-Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs prior to the treatment. Inhaled and topical steroids are allowed. 10-Administration of a vaccine not foreseen by the study protocol during the period starting one month before the application of the study vaccine and ending one month after that application. 11-Anu acute disease, moderate or severe, at the time of enrollment. 12-Do not approve a written examination about cholera.