Efficacy of B7A BSIgG Against E. Coli Strain B7A Challenge

Inclusion Criteria: * Male or female between 18 and 50 years of age, inclusive. * General good health, without significant medical illness, abnormal physical examination findings or clinical laboratory abnormalities as determined by principal investigator (PI) or PI in consultation with the research monitor and sponsor. * Demonstrate comprehension of the protocol procedures and knowledge of ETEC illness by passing a written examination (pass grade ≥ 70%) * Willing to participate after informed consent obtained. * Available for all planned follow-up visits. * Negative serum pregnancy test at screening and negative serum and/or urine pregnancy test on the day of admittance to the inpatient phase for female subjects of childbearing potential. Females of childbearing potential must agree to use an efficacious hormonal or barrier method of birth control during the study. Abstinence is acceptable. Female subjects unable to bear children must have this documented (e.g., tubal ligation or hysterectomy). Exclusion Criteria: General health criteria * Presence of a significant medical condition, (e.g. 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 which in the opinion of the investigator precludes participation in the study. * Immunosuppressive illness or Immunoglobulin A (IgA) deficiency (serum IgA \< 7 mg/dL or below the limit of detection of assay) * Evidence of confirmed infection with HIV, HBsAg, or Hepatitis C Virus (HCV), with confirmatory assays. * Use of any investigational product within 30 days preceding the receipt of the investigational products, or planned use during the active study period * Significant abnormalities in screening lab hematology or serum chemistries, as determined by PI or PI in consultation with the research monitor and sponsor. * Lactation or breastfeeding. Research-related exclusions applicable to challenge * History of microbiologically confirmed ETEC or cholera infection in last 3 years. * Occupation involving handling of ETEC or Vibrio cholerae currently, or in the past 3 years. * Travel to countries where ETEC or cholera infection is endemic (most of the developing world) within 3 years prior to dosing. * Symptoms consistent with Travelers' Diarrhea concurrent with travel to countries where ETEC infection is endemic (most of the developing world) within 3 years prior to dosing, OR planned travel to endemic countries during the length of the study. * Vaccination for or ingestion of ETEC, cholera, or E coli heat labile toxin within 3 years prior to dosing. * Any prior experimental infection with ETEC strain B7A. Study-specific Exclusion Criteria (potential increased risk or complicating outcome ascertainment) * Abnormal stool pattern (fewer than 3 per week or more than 3 per day). * History of diarrhea in the 2 weeks prior to planned inpatient phase. * Regular use of laxatives, antacids, or other agents to lower stomach acidity (regular defined as at least weekly). * Use of antibiotics during the 7 days before receipt of any investigational