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ShigellosisPhase 2S4V03NCT06615375

A Human Challenge Study to Assess Protection of a Shigella Tetravalent Bioconjugate Vaccine

A Phase 2 study testing Shigella4V2 in people with Shigellosis, run by LimmaTech Biologics AG at 3 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

In this challenge study, the bioconjugate candidate vaccine Shigella4V2 will be tested for its ability to induce an immune response that protects healthy adult volunteers from infection with a wild-type Shigella sonnei strain compared to participants receiving placebo. Read more about this study

Who is it for?
Ages 18 to 50 yearsHealthy volunteers can take part
Conditions the study is for
Shigellosis
What is being tested?
Shigella4V2
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
97 participants
Where
3 sitesUnited States
Study dates
12 Nov 2024to 18 Sep 2026
Phase
Phase 2
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 50 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Step 1 and Step 2:
  • Age 18-50 years (inclusive).
  • In good health and stable medical condition, determined by MH, laboratory results, and physical examination during screening period.
  • Negative pregnancy test at the time of 1st injection, for participants of childbearing potential.
  • Persons of childbearing potential must agree to avoid pregnancy by use of effective contraception for 30 days prior to 1st injection and throughout the study. Participants assigned female at birth and unable to bear children must have this documented (e.g., tubal ligation or hysterectomy).
  • Willingness to participate in the study after all aspects of the protocol have been explained and written informed consent obtained.
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  • Availability for the study duration, including all planned follow-up visits and phone calls.
  • Willingness to refrain from participating in other studies of investigational products until completion of the last study contact.
  • Step 2 only:
  • Demonstrated comprehension of the protocol procedures, knowledge of Shigella- associated illness, and passing score of 70% or better on a comprehension assessment. Maximum two attempts are allowed.

Who cannot join

  • Step 1 and Step 2:
  • Participants currently pregnant, lactating, or intending to become pregnant during the study period as reported by the participant.
  • Presence of a significant medical or psychiatric condition which in the opinion of the investigator precludes participation in the study.
  • Clinically significant abnormalities in vital signs or in screening hematology / blood chemistry as determined by the investigator.
  • Presence in the serum of HIV 1/2 antibody, HBs-Ag, or HCV antibody (if confirmed positive by Hepatitis C confirmatory test, i.e., recombinant immunoblot assay (RIBA), polymerase chain reaction (PCR)).
  • Evidence of current excessive alcohol consumption or drug dependence (e.g. according to medical history).
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  • Known or suspected impairment of immunological function (e.g., documented HIV infection, asplenia/splenectomy, or history of autoimmune disease or lymphoproliferative disorder).
  • BMI < 19 or > 35 kg/m2.
  • Recent vaccination or planned vaccination within 14 days of 1st study injection for inactivated vaccines and within 30 days for live vaccines.
  • Recent receipt of an investigational product within 30 days preceding the 1st study injection or planned during the entire study period.
  • Recent treatment with immunoglobulins or blood products within 3 months preceding the 1st study injection or planned use during the entire study period.
  • Use of any medication known to affect the immune function (e.g., systemic steroids) within 30 days preceding the 1st study injection or planned use during the entire study period.
  • Symptoms consistent with Traveler's Diarrhea concurrent with travel to countries where Shigella infection is endemic (most of the developing world).
  • Vaccination for or ingestion of Shigella.
  • Use of systemic antibiotics during the 7 days before 1st injection.
  • Serum IgG titers to S. sonnei LPS ≥ 2500.
  • Current occupation involving the handling of Shigella bacteria.
  • History of allergy to components of the study vaccine (Alhydrogel), to placebo (PBS), or to soy, or any other allergy the investigator deems to increase their risk of AEs in the study.
  • Any other criteria which, in the investigator's opinion, would compromise the ability of the participant to participate in the study, the safety of the study, or the results of the study.
  • Part of study personnel or close family member of personnel conducting the study.
  • Step 2 only:
  • Personal history of inflammatory ReA.
  • Positive blood test for HLA-B27 antigen.
  • Personal history of IBS as defined by Rome IV criteria.
  • Regularly abnormal stool pattern (fewer than 3 per week or more than 3 per day).
  • Regular use of laxatives, antacids, or other agents to lower stomach acidity.
  • Known allergy to challenge agent components.
  • Known allergy to ciprofloxacin or trimethoprim-sulfamethoxazole.
  • Evidence of IgA deficiency (serum IgA < 7 mg/dL or limit of detection of assay).
  • Planning to travel to Shigella endemic countries before completion of the challenge phase of the study.
  • Personal history of inflammatory bowel disease.

Trial locations and contacts

3 sites in 1 country.

United States3 sites

  • Hope Clinic of Emory University

    Atlanta, Georgia, 30030

  • Johns Hopkins Center for Immunization Research

    Baltimore, Maryland, 21205

  • Cincinnati Children's Hospital Medical Center

    Cincinnati, Ohio, 45229

Other trials in United States

About this study

Official title: Phase 2b, Double-blind, Placebo-controlled Efficacy Challenge Study With the Shigella Tetravalent Bioconjugate Vaccine Shigella4V2

In this challenge study, the bioconjugate candidate vaccine Shigella4V2 will be tested for its ability to induce an immune response that protects healthy adult volunteers from infection with a wild-type Shigella sonnei strain compared to participants receiving placebo.

Read the detailed description

The tetravalent Shigella4V2 bioconjugate vaccine candidate will be tested for safety and preliminary efficacy in a Phase 2b controlled human infection model (CHIM) study at three sites in the United States. This trial will be conducted as a parallel-group, randomized, double-blind, multicenter, placebo-controlled study to evaluate the safety, immunogenicity, and efficacy of two injections of Shigella4V2 in healthy Shigella naïve participants 18-50 years of age, with the second injection administered one month before challenge with S. sonnei 53G strain. It will have two steps:

  1. Step 1, a dose confirmation step, in which a first injection of Shigella4V2 (high dose or low dose, adjuvanted with Alhydrogel) will be administered alongside a placebo arm (phosphate-buffered saline) at a ratio of 2:2:1. A second injection of either Shigella4V2 low dose or placebo will be administered about 6 months after the first injection.
  2. Step 2, in which participants will be randomized to the Shigella4V2 dose selected after Step 1 or to placebo at a ratio of 1:1. Participants will receive two injections, 28 days apart. One month after the second injection, they will be challenged with 1500 CFU of the virulent Shigella sonnei strain 53G.
Conditions
Shigellosis
Being tested
Shigella4V2, Placebo
Medical subject headings
Dysentery, Bacillary

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Shigella4V2Biological

    Shigella4V2 is a tetravalent bioconjugate vaccine

  • PlaceboBiological

    Phosphate-buffered saline

Study groups in NCT06615375
Study groupRoleWhat they receive
Shigella4V2 High doseExperimental1 injection of high dose Shigella4V2 and 1 injection of low dose Shigella4V2 will be injected intramuscularly in the deltoid muscle
Receives: Biological: Shigella4V2
Shigella4V2 Low doseExperimental2 injections of low dose of Shigella4V2 will be injected intramuscularly in the deltoid muscle
Receives: Biological: Shigella4V2
PlaceboPlacebo comparator2 injections of PBS will be injected intramuscularly in the deltoid muscle
Receives: Biological: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. To demonstrate that the Shigella4V2 bioconjugate vaccine protects against shigellosis following challenge with the wild type S. sonnei 53G strain.

    The number of challenged participants with shigellosis post-challenge during the inpatient period that received vaccine compared to participants who received placebo. Shigellosis is defined as:

    1. Severe diarrhea; OR
    2. Moderate diarrhea AND [fever OR ≥ 1 at least moderate constitutional/enteric symptoms OR ≥ 2 episodes of vomiting in 24 h]; OR
    3. Dysentery AND [fever OR ≥ 1 at least moderate constitutional/enteric symptoms OR ≥ 2 episodes of vomiting in 24 h]

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccinees vs. placebo

Secondary outcomes (35)

  1. The number of challenged participants with shigellosis post-challenge during the inpatient period that responded to Shigella4V2 vaccine compared to participants who received placebo.

    Occurrence of shigellosis among the challenged participants that responded from the time of challenge until the end of the inpatient monitoring period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo

  2. Efficacy - Number of participants with moderate-to-severe shigellosis

    Occurrence of moderate-to-severe shigellosis post-challenge during the inpatient period. Moderate-to-severe shigellosis is defined as:

    1. Moderate or severe diarrhea AND [fever OR ≥ 1 severe constitutional/enteric symptoms OR ≥ 3 episodes of vomiting in 24 h]; OR
    2. Dysentery AND [fever OR ≥ 1 severe constitutional/enteric symptoms OR ≥ 3 episodes of vomiting in 24 h]

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  3. Efficacy - Number of participants with diarrhea of any severity

    Occurrence of ≥ 2 loose stools in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  4. Efficacy - Number of participants with severe diarrhea

    Occurrence of ≥ 6 loose stools or more than 800 g of stool in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  5. Efficacy - Number of participants with moderate or severe diarrhea

    Occurrence of ≥ 4 loose stools or ≥ 400 g of stool in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  6. Efficacy - Number of participants with more severe diarrhea

    Occurrence of ≥ 10 loose stools or ≥ 1000 g of stool in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  7. Efficacy - Maximum weight of grade 3-5 stools passed in 24 h per participant

    Maximum weight of loose stools (grade 3-5) passed in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  8. Efficacy - Maximum number of grade 3-5 stools passed in 24 h per participant

    Maximum number of loose stools (grade 3-5) passed in any 24-hour period post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  9. Efficacy - Number of participants with moderate or severe constitutional enteric symptoms

    Occurrence of moderate or severe constitutional enteric symptoms post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  10. Efficacy - Number of participants with severe constitutional enteric symptoms

    Occurrence of severe constitutional enteric symptoms post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  11. Efficacy - Number of participants with fever

    Occurrence of fever post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  12. Efficacy - Highest recorded temperature

    Highest recorded temperature post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  13. Efficacy - Time from challenge to onset of diarrhea

    Time (in hours) from challenge to first loose stool that contributes to diarrhea (≥ 2 loose stools in a 24-hour period)

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  14. Efficacy - Time from challenge to onset of shigellosis

    Time (in hours) from challenge to first event (e.g., first loose stool, first day of fever or moderate symptom, or first episode of vomiting) that contributes to the shigellosis endpoint

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  15. Efficacy - Duration of diarrhea

    Duration will be calculated as the time (in hours) from the first stool that contributes to diarrhea until the last stool that contributes to diarrhea, occurring post-challenge during the inpatient period, irrespective of intermittent time without loose stools

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  16. Efficacy - Shigella disease severity score

    Shigella disease severity score (scale from 0 to 9) post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  17. Efficacy - Number of participants requiring early antibiotic therapy

    Receipt of antibiotic therapy prior to 5 days after challenge

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  18. Efficacy - Number of participants requiring IV fluids

    Receipt of IV fluids post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccine responders vs. placebo as well as vaccinees vs. placebo

  19. Efficacy - Number of participants with blood in stool as confirmed by hemoccult

    Occurrence of at least one stool with blood as confirmed by hemoccult post-challenge during the inpatient period

    Measured: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccinees vs. placebo

  20. Safety - Solicited Local and Systemic Adverse Events (AEs)

    Number of participants with solicited AEs, including local and general post-injection

    Measured: To be evaluated after injection in vaccinees vs. placebo during the 7-day follow-up period of each injection (day of administration and 6 following days)

  21. Safety - Unsolicited AEs

    Number of participants with unsolicited AEs post-injection

    Measured: To be evaluated after injection in vaccinees vs. placebo during the 28-day follow-up period after each injection (day of administration and 27 following days)

  22. Safety - All Solicited and Unsolicited AEs post-injection

    Number of participants with any AEs post-injection

    Measured: To be evaluated after injection in vaccinees vs. placebo during the 28-day follow-up period after each injection (day of administration and 27 following days)

  23. Safety - Unsolicited AEs post-challenge

    Number of participants with unsolicited AEs post-challenge

    Measured: To be evaluated after challenge in vaccinees vs. placebo during the 28-day follow-up period post-challenge (day of challenge and 27 following days)

  24. Safety - Medically relevant AEs post-injection

    Number of participants with medically relevant AEs post-injection

    Measured: To be evaluated in vaccinees vs. placebo from 28 days post each injection until receipt of next injection, challenge, or until their study end

  25. Safety - Medically relevant AEs post-challenge

    Number of participants with medically relevant AEs post-challenge

    Measured: To be evaluated in vaccinees vs. placebo from 28 days post-challenge (Day 57) until their study end

  26. Safety - Serious Adverse Events (SAEs)

    Number of participants with SAEs

    Measured: To be evaluated after injection in vaccinees vs. placebo until their study end

  27. Safety - AEs leading to withdrawal from the trial

    Number of participants with AEs leading to withdrawal from the trial

    Measured: To be evaluated after injection in vaccinees vs. placebo until their study end

  28. Safety - Evaluate changes in hematological and blood chemistry parameters following injection

    Number of participants with hematological and blood chemistry laboratory abnormalities

    Measured: To be evaluated at 7-days of each post-injection compared to baseline values in vaccinees vs. placebo

  29. Immunogenicity - Geometric mean titers (GMTs) of anti-S. sonnei LPS IgGs in serum

    Anti-S. sonnei LPS IgG titer in serum collected at V1, V2, V3, V4, V5/a/b, V6, V7 and V8 in Step 1, and at V1, V2, V3, V4, C-1, C8, and V6 in Step 2

    Measured: To be evaluated in vaccinees vs. placebo from Day 1 until study end

  30. Immunogenicity - GMTs of anti-S. flexneri 2a LPS IgGs in serum

    Anti-S. flexneri 2a LPS IgG titer in serum collected at V1, V2, V3, V4, V5/a/b, V6, V7 and V8 in Step 1, and at V1, V2, V3, V4, C-1, C8, and V6 in Step 2

    Measured: To be evaluated in vaccinees vs. placebo from Day 1 until study end

  31. Immunogenicity - GMTs of anti-S. flexneri 3a LPS IgGs in serum

    Anti-S. flexneri 3a LPS IgG titer in serum collected at V1, V2, V3, V4, V5/a/b, V6, V7 and V8 in Step 1, and at V1, V2, V3, V4, C-1, C8, and V6 in Step 2

    Measured: To be evaluated in vaccinees vs. placebo from Day 1 until study end

  32. Immunogenicity - GMTs of anti-S. flexneri 6 LPS IgGs in serum

    Anti-S. flexneri 6 LPS IgG titer in serum collected at V1, V2, V3, V4, V5/a/b, V6, V7 and V8 in Step 1, and at V1, V2, V3, V4, C-1, C8, and V6 in Step 2

    Measured: To be evaluated in vaccinees vs. placebo from Day 1 until study end

  33. Immunogenicity - establish or confirm immunomarker that correlate with a reduced risk of shigellosis

    Association between the primary shigellosis outcome and each of the following:

    • Serum anti-S. sonnei LPS IgG titer at C-1 (pre-challenge)
    • Maximum post-vaccination serum anti-S. sonnei LPS IgG titer through C-1 (pre-challenge)
    • Fold change from V1 (baseline) to C-1 (pre-challenge) in serum anti-S. sonnei LPS IgG titer

    Measured: To be evaluated in challenged vaccinees from Day 1 to Day 65

  34. Immunogenicity - establish or confirm immunomarker that correlate with a reduced risk of moderate-to-severe shigellosis

    Association between moderate-to-severe shigellosis and each of the following:

    • Serum anti-S. sonnei LPS IgG titer at C-1 (pre-challenge)
    • Maximum post-vaccination serum anti-S. sonnei LPS IgG titer through C-1 (pre-challenge)
    • Fold change from V1 (baseline) to C-1 (pre-challenge) in serum anti-S. sonnei LPS IgG titer

    Measured: To be evaluated in challenged vaccinees from Day 1 to Day 65

  35. Immunogenicity - establish or confirm immunomarker that correlate with a reduced risk of solicited events

    Association between the occurrence (any severity) and severity of each solicited event following challenge and each of the following:

    • Serum anti-S. sonnei LPS IgG titer at C-1 (pre-challenge)
    • Maximum post-vaccination serum anti-S. sonnei LPS IgG titer through C-1 (pre-challenge)
    • Fold change from V1 (baseline) to C-1 (pre-challenge) in serum anti-S. sonnei LPS IgG titer

    Measured: To be evaluated in challenged vaccinees from Day 1 to Day 65

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Sep 2024
  2. Study start12 Nov 2024
  3. Primary completion14 Apr 2026
  4. Study completion18 Sep 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
97 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06615375
Sponsor's protocol ID
S4V03
Acronym
S4V03
Status last verified
Sep 2026
First submitted
20 Sep 2024
Last updated
1 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Clarkson KA, Talaat KR, Alaimo C, Martin P, Bourgeois AL, Dreyer A, Porter CK, Chakraborty S, Brubaker J, Elwood D, Frolich R, DeNearing B, Weerts HP, Feijoo B, Halpern J, Sack D, Riddle MS, Fonck VG, Kaminski RW. Immune response characterization in a human challenge study with a Shigella flexneri 2a bioconjugate vaccine. EBioMedicine. 2021 Apr;66:103308. doi: 10.1016/j.ebiom.2021.103308. Epub 2021 Apr 1.

    PubMed 33813141

  • Cohen D, Ashkenazi S, Green MS, Gdalevich M, Robin G, Slepon R, Yavzori M, Orr N, Block C, Ashkenazi I, Shemer J, Taylor DN, Hale TL, Sadoff JC, Pavliakova D, Schneerson R, Robbins JB. Double-blind vaccine-controlled randomised efficacy trial of an investigational Shigella sonnei conjugate vaccine in young adults. Lancet. 1997 Jan 18;349(9046):155-9. doi: 10.1016/S0140-6736(96)06255-1.

    PubMed 9111538

  • Cohen D, Ashkenazi S, Green M, Lerman Y, Slepon R, Robin G, Orr N, Taylor DN, Sadoff JC, Chu C, Shiloach J, Schneerson R, Robbins JB. Safety and immunogenicity of investigational Shigella conjugate vaccines in Israeli volunteers. Infect Immun. 1996 Oct;64(10):4074-7. doi: 10.1128/iai.64.10.4074-4077.1996.

    PubMed 8926071

  • Frenck RW Jr, Dickey M, Suvarnapunya AE, Chandrasekaran L, Kaminski RW, Clarkson KA, McNeal M, Lynen A, Parker S, Hoeper A, Mani S, Fix A, Maier N, Venkatesan MM, Porter CK. Establishment of a Controlled Human Infection Model with a Lyophilized Strain of Shigella sonnei 53G. mSphere. 2020 Sep 23;5(5):e00416-20. doi: 10.1128/mSphere.00416-20.

    PubMed 32968005

  • Hausdorff WP, Anderson JD 4th, Bagamian KH, Bourgeois AL, Mills M, Sawe F, Scheele S, Talaat K, Giersing BK. Vaccine value profile for Shigella. Vaccine. 2023 Nov 3;41 Suppl 2:S76-S94. doi: 10.1016/j.vaccine.2022.12.037. Epub 2023 Oct 10.

    PubMed 37827969

  • Kotloff KL, Riddle MS, Platts-Mills JA, Pavlinac P, Zaidi AKM. Shigellosis. Lancet. 2018 Feb 24;391(10122):801-812. doi: 10.1016/S0140-6736(17)33296-8. Epub 2017 Dec 16.

    PubMed 29254859

  • MacLennan CA, Aguilar AO, Steele AD. Consensus Report on Shigella Controlled Human Infection Model: Introduction and Overview. Clin Infect Dis. 2019 Dec 9;69(Suppl 8):S577-S579. doi: 10.1093/cid/ciz886.

    PubMed 31816066

  • MacLennan CA, Grow S, Ma LF, Steele AD. The Shigella Vaccines Pipeline. Vaccines (Basel). 2022 Aug 24;10(9):1376. doi: 10.3390/vaccines10091376.

    PubMed 36146457

  • Martin P, Alaimo C. The Ongoing Journey of a Shigella Bioconjugate Vaccine. Vaccines (Basel). 2022 Jan 29;10(2):212. doi: 10.3390/vaccines10020212.

    PubMed 35214671

  • Passwell JH, Ashkenazi S, Banet-Levi Y, Ramon-Saraf R, Farzam N, Lerner-Geva L, Even-Nir H, Yerushalmi B, Chu C, Shiloach J, Robbins JB, Schneerson R; Israeli Shigella Study Group. Age-related efficacy of Shigella O-specific polysaccharide conjugates in 1-4-year-old Israeli children. Vaccine. 2010 Mar 2;28(10):2231-2235. doi: 10.1016/j.vaccine.2009.12.050. Epub 2010 Jan 5.

    PubMed 20056180

  • Porter CK, Thura N, Ranallo RT, Riddle MS. The Shigella human challenge model. Epidemiol Infect. 2013 Feb;141(2):223-32. doi: 10.1017/S0950268812001677. Epub 2012 Aug 21.

    PubMed 22906296

  • Porter CK, Lynen A, Riddle MS, Talaat K, Sack D, Gutierrez RL, McKenzie R, DeNearing B, Feijoo B, Kaminski RW, Taylor DN, Kirkpatrick BD, Bourgeois AL. Clinical endpoints in the controlled human challenge model for Shigella: A call for standardization and the development of a disease severity score. PLoS One. 2018 Mar 28;13(3):e0194325. doi: 10.1371/journal.pone.0194325. eCollection 2018.

    PubMed 29590182

  • Riddle MS, Kaminski RW, Di Paolo C, Porter CK, Gutierrez RL, Clarkson KA, Weerts HE, Duplessis C, Castellano A, Alaimo C, Paolino K, Gormley R, Gambillara Fonck V. Safety and Immunogenicity of a Candidate Bioconjugate Vaccine against Shigella flexneri 2a Administered to Healthy Adults: a Single-Blind, Randomized Phase I Study. Clin Vaccine Immunol. 2016 Dec 5;23(12):908-917. doi: 10.1128/CVI.00224-16. Print 2016 Dec.

    PubMed 27581434

  • Talaat KR, Alaimo C, Martin P, Bourgeois AL, Dreyer AM, Kaminski RW, Porter CK, Chakraborty S, Clarkson KA, Brubaker J, Elwood D, Frolich R, DeNearing B, Weerts H, Feijoo BL, Halpern J, Sack D, Riddle MS, Fonck VG. Human challenge study with a Shigella bioconjugate vaccine: Analyses of clinical efficacy and correlate of protection. EBioMedicine. 2021 Apr;66:103310. doi: 10.1016/j.ebiom.2021.103310. Epub 2021 Apr 13.

    PubMed 33862589

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Shigella4V2 in people with Shigellosis, run by LimmaTech Biologics AG at 3 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 31 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

To demonstrate that the Shigella4V2 bioconjugate vaccine protects against shigellosis following challenge with the wild type S. sonnei 53G strain. (time frame: To be evaluated post-challenge during the inpatient period (Day 56 through Day 65) in vaccinees vs. placebo). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06615375, which also lists 14 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Oct 2026.

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