Shigella CVD 31000: Study of Responses With Shigella-ETEC Vaccine Strain CVD 1208S-122

Phase 1 Study of the Safety, Tolerability, and Immunogenicity of Oral Doses of CVD 1208S-122, a Prototype Attenuated Shigella Flexneri 2a Live Vector Expressing Enterotoxigenic Escherichia Coli Antigens

The purpose of this study is to determine whether a live, oral, combined Shigella-ETEC vaccine candidate, known as strain CVD 1208S-122, is safe and immunogenic.

Study Overview

• Status: Completed
• Conditions: Shigella Infection; Enterotoxigenic Escherichia Coli Infection
• Intervention / Treatment: Biological: strain CVD 1208S-122; Other: Placebo

Detailed Description

The purpose of this study is to determine whether a live, oral, combined Shigella-ETEC vaccine candidate, known as strain CVD 1208S-122, is safe and immunogenic. This will be a phase 1, double-blind, placebo-controlled, dose-escalating, single-center study, involving three vaccine dosage escalation cohorts (10^8, 10^9, and 10^10 cfu vaccine organisms). Each of the three dose-escalation cohorts will consist of 8 study participants who will be randomly allocated to receive either vaccine (n=6) or placebo (n=2), as a single, oral dose. An independent Safety Monitoring Committee (SMC) will review the available safety data for Cohorts 1 - 3 through 7 days post-vaccination before proceeding to the enrollment of the next cohort. The fourth cohort will be an adaptive design cohort consisting of 30 study participants to be randomly allocated to receive either two doses of vaccine (n=12), one dose of vaccine (n=12), or two doses of placebo (n=6), with the dosage selection based on the highest well-tolerated dose in the dose-escalation cohorts (1 - 3), as determined by the SMC.

Each of the dose-escalation cohorts (1 - 3) will receive the oral dose of blinded study product while in the inpatient setting. During the following subsequent 96 hours (4 days), participants will remain on the inpatient research isolation ward to be closely monitored, and each stool will be collected by study staff. The evaluation and monitoring of participants enrolled in the fourth cohort will be conducted entirely in the outpatient setting.

• Study Type: Interventional
• Enrollment (Actual): 53
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland, Baltimore, University of Maryland School of Medicine, Center for Vaccine Development and Global Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 49 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male or female, 18 - 49 years of age
• Written informed consent provided

• Determined to be in good health* based on medical history and review of concomitant medications

  *Good health as defined by an absence of an active chronic medical condition which requires daily prescription medication(s). Participants may be eligible if the medical condition only requires infrequent as needed (PRN) medication and if the investigator determines that the condition does not pose a risk to participant safety or the assessment of reactogenicity and immunogenicity. Any chronic medical condition which does not require a daily prescription medication but might pose a risk to a participant with rapid dehydration (i.e., rapid intravascular volume changes) would be ineligible to participate.

• Documented acceptable results from screening laboratory work (defined in Appendix B), including:

  • Complete blood count (CBC) with differential for total white blood cell count (WBC), absolute neutrophil count (ANC), hemoglobin (Hg), platelet count
  • Creatinine, alanine aminotransferase (ALT), total bilirubin
  • Serum Immunoglobulin A (IgA) level
  • Human immunodeficiency virus (HIV) antibody, Hepatitis B surface antigen (HBsAg), Hepatitis C virus antibody (HCV)
  • HLA-B27 histocompatibility testing
  • Serum Beta human chorionic gonadotropin (β-HCG) test, if the participant is a woman of child-bearing potential
• A passing score (≥70%) on a Comprehension Assessment Tool
• Agrees not to participate in another clinical trial during the study period

• Females of child-bearing potential† agree to use an acceptable form of birth control‡ from enrollment and through at least 4 weeks after vaccination

  †Females of child-bearing potential, defined as having not been sterilized via tubal ligation, bilateral oophorectomy, salpingectomy, hysterectomy, or successful Essure® placement (permanent, non-surgical, non-hormonal sterilization) with documented radiological confirmation test at least 90 days after the procedure, and still menstruating or <1 year has passed since the last menses, if menopausal.

  ‡Acceptable birth control includes barrier methods such as condoms or diaphragms/cervical cap with spermicide; effective intrauterine devices; NuvaRing®; and licensed hormonal methods such as implants, injectables or oral contraceptives ("the pill") or alternatively, monogamous relationship with a vasectomized partner who has been vasectomized for 180 days or more prior to the subject receiving the study vaccination, abstinence from sexual intercourse with a male partner, or sexual relationships with non-male partners.

• Available for up to a 6-day inpatient stay
• For Participants of Cohorts 1-3 during the time when a U.S. Public Health Emergency for COVID-19 exists, SARS-CoV-2 testing must be performed upon admission to the inpatient ward and must document a negative test result prior to vaccination.

Exclusion Criteria:

• A positive pregnancy test at screening or within 24 h prior to study product dosing
• A female who is breastfeeding
• Poor venous access, as defined by inability to obtain venous blood, for screening labs, after 3 venipuncture attempts

• Abnormal vital signs, defined as:

  • Systolic BP >150 mmHg or Diastolic BP >90 mmHg
  • Resting heart rate >100 bpm
  • Oral temperature ≥38.0°C
• Having received prior vaccines for or have had prior infection with ETEC, LT, cholera, or Shigella, within the past 3 years
• History of diarrhea during travel to a developing country within the past 3 years
• History of chronic gastrointestinal illness, including severe dyspepsia, lactose intolerance, or another significant gastrointestinal tract disease (e.g., irritable bowel syndrome, inflammatory bowel syndrome, gastric ulcer disease)
• Regular use (≥once weekly) of laxatives, anti-diarrheal agents, anti-constipation agents, or antacid therapies
• History of major gastrointestinal surgery (uncomplicated laparoscopic appendectomy or cholecystectomy >1-year prior is permitted)
• Abnormal bowel habits, as defined by <3 stools per week or >2 stools per day in the past 6 months

• Use of systemic antimicrobials§ within the past 2 weeks

  • use of topical (skin), otic, or ophthalmic antibiotics is acceptable, if those doses are not expected to result in significant systemic absorption levels
• Use of oral, parenteral or high-dose inhaled steroids within 30 days

• Use of any medication which might affect immune function# within 30 days

  #examples include anti-cancer drugs, immunomodulating monoclonal antibody therapeutics, and rheumatologic therapies

• Diagnosis of schizophrenia or other major psychiatric disease
• Alcohol or drug abuse within last 5 years
• Presence of immunosuppression, which could be due to active neoplastic disease or a history of any hematologic malignancy (excluding resolved non-melanoma skin cancers), radiation therapy, or primary or secondary immunodeficiencies
• History of allergy to quinolone (e.g., ciprofloxacin) or sulpha drugs (e.g., trimethoprim-sulfamethoxazole)
• Known history of seizure disorder (remote history of a childhood seizure disorder which has completely resolved is acceptable)
• Occupation involving the handling of ETEC, cholera, or Shigella bacteria
• Occupation in food handling industry or care of very young children (<2 years old), elderly (≥70 years), or immunocompromised
• During the time when a U.S. Public Health Emergency for COVID-19 exists, within 14 days prior to the time of vaccination, the presence of 2 or more of any of the following symptoms: fever (≥38°C, chills, myalgia, headache, sore throat, or new olfactory and taste disorder
• During the time when a U.S. Public Health Emergency for COVID-19 exists, within 14 days prior to the time of vaccination, the presence of 1 or more of any of the following respiratory symptoms: cough which cannot otherwise be explained, shortness of breath, or difficulty breathing
• Any other criteria which, in the investigator's opinion, would compromise the safety of the study, the ability of a subject to participate, or the results of the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1: Shigella Vaccine at 10^8 cfu or Placebo; 3:1 randomization to one dose of vaccine or placebo (Cohort n=8)	Biological: strain CVD 1208S-122; Live, attenuated, vaccine strain of S. flexneri 2a expressing CFA/I and LT of enterotoxigenic E. coli; Other: Placebo; Sodium bicarbonate buffer
Experimental: Cohort 2: Shigella Vaccine at 10^9 cfu or Placebo; 3:1 randomization to one dose of vaccine or placebo (Cohort n=8)	Biological: strain CVD 1208S-122; Live, attenuated, vaccine strain of S. flexneri 2a expressing CFA/I and LT of enterotoxigenic E. coli; Other: Placebo; Sodium bicarbonate buffer
Experimental: Cohort 3: Shigella Vaccine at 10^10 cfu or Placebo; 3:1 randomization to one dose of vaccine or placebo (Cohort n=8)	Biological: strain CVD 1208S-122; Live, attenuated, vaccine strain of S. flexneri 2a expressing CFA/I and LT of enterotoxigenic E. coli; Other: Placebo; Sodium bicarbonate buffer
Experimental: Cohort 4: Shigella Vaccine or Placebo; 2:2:1 randomization to receive either two doses of vaccine, 1 dose of vaccine and one dose of placebo, or two doses of placebo at Days 1 and 29 (Cohort n=30)	Biological: strain CVD 1208S-122; Live, attenuated, vaccine strain of S. flexneri 2a expressing CFA/I and LT of enterotoxigenic E. coli; Other: Placebo; Sodium bicarbonate buffer

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participants Experiencing Fever, Diarrhea, or Dysentery; Solicited Local Adverse Events; Solicited Systemic Adverse Events; and Clinical Safety Laboratory Adverse Events	Participants experiencing fever, diarrhea, or dysentery; solicited local adverse events; solicited systemic adverse events; and clinical safety laboratory adverse events	Solicited AEs: Cohorts 1-3 during 4 days of inpatient and memory aid for another 3 days; Cohort 4 memory aid over 7 days after each dose of study product Clinical Safety Labs: Cohorts 1-3: Day 1 and Day 8; Cohort 4: Days 1 and 29 and Days 8 and 36
Vaccine Organisms Shed in Stools in Cohorts 1-3 - Cohorts 1-3	Vaccine organisms shed in stools in Cohorts 1-3	7 days
Vaccine Organisms Shed in Stools in Cohort 4	Vaccine organisms shed in stools in Cohort 4	2 days
Number of Participants With Genetically Stable Fecal Shed Organisms	Fecal shed organisms found to be genetically stable, as defined as being PCR positive for Shigella (ipaH or virG), CFA/I (cfaB), and LTB (eltB)	7 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participants With ELISA Antibody Responses	Seroconversions (defined as 4-fold or higher compared to baseline) in antigen-specific ELISA antibody responses	28 days
Participants With ASC Responses	Responses (defined as ≥8 spot forming cells/10^6 PBMC) in antigen-specific ASC responses post-vaccination	7 days

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Investigators: Principal Investigator: Wilbur Chen, MD, MS, Center for Vaccine Development and Global Health, University of Maryland School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): September 29, 2022
• Primary Completion (Actual): October 1, 2024
• Study Completion (Actual): October 1, 2024

Study Registration Dates

• First Submitted: November 11, 2020
• First Submitted That Met QC Criteria: November 17, 2020
• First Posted (Actual): November 18, 2020

Study Record Updates

• Last Update Posted (Actual): February 2, 2026
• Last Update Submitted That Met QC Criteria: January 30, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: vaccine; strain CVD 1208S-122
• Additional Relevant MeSH Terms: Intestinal Diseases; Infections; Digestive System Diseases; Gastrointestinal Diseases; Gastroenteritis; Bacterial Infections; Bacterial Infections and Mycoses; Gram-Negative Bacterial Infections; Enterobacteriaceae Infections; Dysentery; Dysentery, Bacillary
• Other Study ID Numbers: HP-00094148

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No