A Phase 3 interventional study of S. Flexneri-S. Sonnei bivalent conjugate vaccine and Placebo in Dysentery and Dysentery, Shigella, sponsored by Beijing Zhifei Lvzhu Biopharmaceutical Co., Ltd. Active, not recruiting at 1 site in Bangladesh. Open to participants aged 6 Months to 5 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-01.
Sponsored by Beijing Zhifei Lvzhu Biopharmaceutical Co., Ltd (part of Chongqing Zhifei Biological Products Co., Ltd.) · Phase 3, Interventional, and Prevention
The goal of this clinical trial is to evaluate the protective efficacy of S. Flexneri-S. Sonnei bivalent conjugate vaccine against diarrhea caused by Shigella infection in infants and children aged 6 months to 5 years. Researchers will observe the incidence of diarrhea of any severity due to Shigella flexneri and Shigella sonnei infection 30 days after full immunization. The subjects will receive 2 doses of vaccination.
61 studies on the registry are indexed under Dysentery, Bacillary; 6 are open to participants now.
This study's planned enrollment of 8,000 is above the median of 76 across 54 interventional studies indexed under Dysentery, Bacillary.
Browse Dysentery, Bacillary studies →Beijing Zhifei Lvzhu Biopharmaceutical Co., Ltd is the lead sponsor of 22 studies on the registry; 5 are open to participants now.
Compared within Dysentery, Bacillary, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Dysentery. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Currently suffering from the following diseases:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
4000 subjects aged 6 months to 5 years are enrolled in this group.
Biological: S. Flexneri-S. Sonnei bivalent conjugate vaccine
4000 subjects aged 6 months to 5 years are enrolled in this group.
Biological: Placebo
Subjects receive two doses of the vaccine on the day of randomisation (day 0) and day 30.
Subjects receive two doses of the placebo on the day of randomisation (day 0) and day 30.
The protective efficacy of S. Flexneri-S. Sonnei bivalent conjugate vaccine
The efficacy will be assessed by comparing the incidence rate of laboratory-confirmed S. flexneri-associated or S. sonnei-associated diarrhea between the vaccinated group and the placebo group. Statistical Analysis: Protective efficacy(%)=(control group incidence (person-year incidence)- vaccine group incidence (person -year incidence))/control group incidence (person-year incidence)x100%
Time frame: From day 30 post full immunization to the subsequent 24-month period.
The protective efficacy against diarrhea cases with positive bacterial culture for Shigella species
Evaluation of the protective efficacy of the vaccine against diarrhea cases with positive bacterial culture for Shigella species.
Time frame: From he first dose of immunization to 24-month period post full immunization.
Positive PCR testing for Shigella species
Evaluation of diarrhea cases with positive PCR testing for Shigella species
Time frame: From day 30 post full immunization to the subsequent 24-month period.
IgG antibody seroconversion (fourfold increase) rate on day 30 post full immunization for subgroup 1.
Subjects in immunogenicity subgroup 1, vaccine serotype-specific Shigella flexneri and Shigella sonnei IgG antibody seroconversion (fourfold increase) rate on day 30 post full immunization.
Time frame: The 30th day after two doses of the vaccine.
IgG antibody concentration on day 30 post full immunization for subgroup 1.
For subjects in immunogenicity subgroup 1, vaccine serotype-specific Shigella flexneri and Shigella sonnei antibody concentration on day 30 post full immunization.
Time frame: The 30th day after two doses of the vaccine.
IgG antibody seroconversion (fourfold increase) rate on day 30 post full immunization for subgroup 2.
For subjects in immunogenicity subgroup 2, vaccine serotype-specific Shigella flexneri and Shigella sonnei IgG antibody seroconversion (fourfold increase) rate on day 30 post the first dose, day 30 post full immunization, half a year after the first immunization, and one year after the first immunization.
Time frame: From 30 day to 1 year after the first immunization.
IgG antibody concentration on day 30 post full immunization for subgroup 2.
For subjects in immunogenicity subgroup 2, vaccine serotype-specific Shigella flexneri and Shigella sonnei antibody concentration on day 30 post the first dose, day 30 post full immunization, half a year after the first immunization, and one year after the first immunization.
Time frame: From 30 day to 1 year after the first immunization.
AEs within 0-30 minutes after vaccination
The occurrence of any adverse events within 30 minutes after each dose of vaccine (number of instances, number of cases, incidence rate, and the relationship to the vaccine administration)
Time frame: Within 30 minutes after each dose of vaccine
Solicited AEs within 0-7 days after vaccination
The occurrence of solicited adverse events from Day 0 to Day 7 after each vaccine dose (number of instances, number of cases, incidence rate, and the relationship to the vaccine administration)
Time frame: Within 0-7 days after each vaccine dose.
Unsolicited AEs within 0-30 days after vaccination
The occurrence of unsolicited adverse events from Day 0 to Day 30 after each vaccine dose (number of instances, number of cases, incidence rate, and the relationship to the vaccine administration).
Time frame: Within 0-30 days after each vaccination
SAE within 0-6 months after primary immunization
The occurrence of Serious Adverse Events (SAEs) from after the first dose to 6 months after complete immunization (number of instances, number of cases, incidence rate, and the relationship to the vaccine administration)
Time frame: Within 0-6 months after primary immunization.
Started May 2025 (actual). Primary completion is estimated for Jul 2028, 37 months after the start.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Beijing Zhifei Lvzhu Biopharmaceutical Co., Ltd →