New malaria vaccine candidate enters human trial in thailand
NCT ID NCT05380388
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This phase II trial tests a new malaria vaccine called PvRII/Matrix-M in 36 healthy Thai adults aged 20-55. Half receive the vaccine, half a placebo. After three doses, 24 volunteers will be exposed to the malaria parasite in a controlled setting to see if the vaccine reduces infection. The study focuses on safety and immune response.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- PvRII/Matrix-M malaria vaccine
- What this could lead to
- If successful, this could lead to a vaccine that protects against Plasmodium vivax malaria, a major cause of illness in tropical regions.
- What could go wrong
- This is a small early-phase trial (36 people) testing safety and immune response, not yet proven to prevent malaria in the real world. The vaccine may not work as hoped.
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
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Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
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About 36 people
The number the study aims to enrol. It can still change while the study runs.
- Expected to start
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Jan 2027
An estimate. Start dates often move.
- Expected to finish
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Dec 2027
An estimate. End dates often move.
- Lead sponsor
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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 55 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 Thai adults aged 20 to 55 years 2. Minimum educational level of high school or equivalent 3. Red blood cells positive for the Duffy antigen/chemokine receptor (DARC) 4. Women only: Must practice continuous effective contraception for the duration of the study period until 3 months post-challenge. 5. Agreement to refrain from blood donation during the study and for 1 year after the initiation of antimalarial treatment. 6. Willing to be admitted to the Hospital for Tropical Diseases for clinical monitoring as required by the protocol until antimalarial treatment is completed and their symptoms are settling, willing to take a curative antimalarial treatment following CHMI, and willing to reside in Bangkok and its vicinity for 2 months after malarial treatment initiation. 7. Able to read and write in Thai. 8. Provide written informed consent to participate in the trial 9. Answer all questions on the informed consent quiz correctly 10. Completed COVID-19 vaccination with 2 doses of any WHO-approved vaccine Exclusion Criteria: 1. Positive malaria qPCR OR malaria film prior to vaccination and challenge 2. Presence of any medical condition (either physical or psychological) that, in the judgment of the investigator, would place the participant at undue risk (including the history of clinically significant contact dermatitis) or interfere with the results of the study (e.g., underlying cardiac, renal, hepatic or neurological disease; severe malnutrition; congenital defects or febrile condition) 3. Presence of chronic disease or chronic use of medication 4. Prior receipt of other investigational vaccine which is likely to impact the interpretation of the trial data as assessed by the Investigator. 5. Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection, asplenia, history of splenectomy, recurrent severe infections, and chronic infection 6. Immunosuppressant medication within the past 6 months preceding enrolment (D0) or plan to use during the study (inhaled and topical steroids are allowed) 7. History of allergic disease or reactions likely to be exacerbated by malaria infection 8. Female participant who is pregnant as evidenced by positive beta-human chorionic gonadotropin (β-HCG) test, or who is lactating or planning pregnancy during the course of the study. 9. Contraindications to the use of antimalarial treatment (e.g., chloroquine, atovaquone/proguanil, or dihydroartemisinin/piperaquine) 10. Use of medications known to have potentially clinically significant interaction with the antimalarial drugs that will be used in this study (chloroquine, atovaquone/proguanil, or dihydroartemisinin/piperaquine) 11. History of cardiac arrhythmia, including clinically relevant bradycardia or Known existing positive family history in both 1st AND 2nd-degree relatives \< 50 years old for cardiac disease 12. Family history of congenital QT prolongation or sudden death 13. Any clinical condition, including using medications known to prolong the QT interval or screening electrocardiogram (ECG), demonstrates a QTc interval ≥ 450 ms. 14. Suspected or known history of alcohol abuse or history of drug abuse. 15. Concurrently participating in another clinical study, at any time during the study period 16. Positive hepatitis B surface antigen or seropositive for hepatitis C virus, or HIV 17. Finding on safety laboratory values as defined below: * Abnormal ALT \[\>upper normal range\] * Abnormal serum creatinine \[\>upper normal range\] * Clinically significant abnormalities in corrected calcium and magnesium blood levels * Haemoglobin \< 11 g/dL 18. Blood group Rhesus negative 19. Blood incompatibility to the inoculum 20. History of allergic disease or reactions likely to be exacerbated by any component of the vaccine 21. Any history of anaphylaxis in reaction to vaccinations Vaccination and re-vaccination exclusion criteria 1\. Acute disease at the time of vaccination. (acute disease is defined as the presence of a moderate or severe illness with or without fever). The following adverse events associated with vaccine immunisation constitute absolute contraindications to further vaccine administration. If any of these events occur during the study, the participant must be withdrawn and followed until the resolution of the event, as with any adverse event: 1. Anaphylactic reaction following administration of the vaccine 2. Pregnancy Exclusion criteria on the day of CHMI The following constitute absolute contraindications to CHMI: 1. Acute disease, defined as a moderate or severe illness with or without fever 2. Pregnancy 3. Use of systemic antibiotics with known antimalarial activity in the 30 days before challenge (e.g., trimethoprim-sulfamethoxazole, doxycycline, tetracycline, clindamycin, erythromycin, fluoroquinolones, and azithromycin)
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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.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
1 site. The list below names each one and where it is.
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The official record
ClinicalTrials.gov lists the study team's own contact details, including names and phone numbers. We don't republish those.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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Faculty of Tropical Medicine
Bangkok, 10400, Thailand
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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- Scientists deliberately infect volunteers with malaria to advance research
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- Scientists bite back: testing malaria infection with live mosquitoes