Could a vaccine finally stop the 'Snail Fever'?
NCT ID NCT05762393
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study tested a new vaccine called SchistoShield® in 120 healthy adults in Burkina Faso and Madagascar. The goal was to see if it is safe and triggers an immune response against schistosomiasis, a parasitic disease spread by snails. Participants received three doses of the vaccine or a placebo, with different strengths being tested.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- SchistoShield® vaccine (rSm-p80 antigen with GLA-SE adjuvant)
- What this could lead to
- If successful, this could lead to the first vaccine to prevent schistosomiasis, a parasitic disease affecting millions.
- What could go wrong
- This is an early Phase 1b trial focused on safety and immune response, not yet on preventing infection. The vaccine may not provide sufficient protection or could have side effects.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 1
The first testing in people. Mainly checks safety and dose, usually in a small group.
- Participants
-
120 people
The number who actually took part.
- Started
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Nov 2023
- Finished
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May 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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20 to 59 years
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Healthy male or female participants aged 20 to 59 years at the time of consent. 2. Participant who has completed the deworming using praziquantel (PZQ) and albendazole (ABZ) according to local guidelines, with the last dose of PZQ/ABZ administered at least 5 weeks prior to first dose of study product. 3. Participant who, after the nature of the study has been explained, has voluntarily given informed consent, according to the local regulatory requirements, prior to study entry. 4. Participant who can comply with the study procedures and available for the entire duration of the study (32 weeks). 5. Individuals in good health as determined by the outcome of medical history, physical examination, hematology and biochemistry tests at the time of screening and the clinical judgment of the investigator. 6. Women of childbearing potential\* with negative urinary test result on a human chorionic gonadotropin pregnancy test on the day of randomization, before receiving any study product. 7. Males or females of childbearing potential who are using an effective birth control method recommended by the national health system for at least four (4) weeks before the first vaccination (for female participants only) and up to four (4) weeks after the third vaccination (i.e., for at least 4 months). Exclusion Criteria: 1. Participant with major congenital abnormalities which in the opinion of investigator may affect the subject's participation in the study. 2. Participant concomitantly enrolled or scheduled to be enrolled in another trial. 3. Positive rapid test for HIV 1-2 confirmed by a positive blood test for human immunodeficiency virus (positive antibodies to HIV 1/2). 4. Participant seropositive for hepatitis B virus surface antigen (HBsAg). 5. Participant seropositive for hepatitis C virus (Antibodies to HCV). 6. Participant with active or chronic Schistosomiasis infection defined by a positive result for microscopy (Urine filtration, Kato-Katz (KK)) and point-of-care - circulating cathodic antigen (POC -CCA) and/or real-time PCR. 7. Participant with soiled transmitted helminths infections (STH) as diagnosed by microscopy (KK) and/or real-time PCR. 8. Participant with malaria infection/malaria as diagnosed by the blood smear. 9. Any other confirmed or suspected immunosuppressive or immunodeficient state such as asplenia, recurrent severe infections. 10. Body mass index (BMI) ≥ 35 kg/m2 11. Chronic use of systemic steroids (\>2 mg/kg/day or \>20 mg/day prednisolone equivalent for periods exceeding 10 days), cytotoxic or other immunosuppressive drugs. 12. Receipt of blood or blood-derived products in the past 3 months. 13. Participant who has received other vaccines 4 weeks prior to test vaccination or plans to receive any vaccine within 4 weeks of last dose of study vaccine, exception made for COVID-19 vaccines. 14. Known history of allergy to study vaccine components and/or excipients or other medications, or any other allergies deemed by the investigator to increase the risk of an adverse event if they were to participate in the trial. 15. Individuals with a known bleeding diathesis, or any condition that may be associated with a prolonged bleeding time resulting in contraindication for IM injections/blood extractions. 16. Any abnormality or chronic disease which in the opinion of the investigator might be detrimental for the safety of the participant and interfere with the assessment of the study objectives and compromise the health of the volunteers. 17. Any female participant who is lactating\*, pregnant or planning for pregnancy\*\* during the course of study period. 18. Individuals with behavioral or cognitive impairment or psychiatric disease or neural disorders that, in the opinion of the investigator, could interfere with the individual's ability to participate in the trial. 19. Any clinically significant abnormal finding on serum chemistry or hematology or urinalysis at the screening visit as per US FDA toxicity grading scale for healthy adult and adolescent volunteers enrolled in preventive vaccine clinical trials (any biological finding grade 4 constitutes an exclusion criteria). 20. Individuals who were research staff involved with the clinical study or family/household members of research staff. 21. As per Investigator's medical judgement individual could be excluded from the study despite meeting all inclusion/exclusion criteria mentioned above.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Groupe de Recherche Action en Santé (GRAS)
Ouagadougou, Burkina Faso
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Madagascar Institute for Vaccine Research (University of Antananarivo)
Antananarivo, Madagascar
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Other studies related to the condition(s) this trial covers.
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