Dengue vaccine trial aims to protect seniors
NCT ID NCT06891950
First seen Jun 26, 2026 · Last updated Jul 17, 2026 · Updated 5 times
Summary
This study tests a dengue vaccine in adults aged 60 to 79 and compares their immune response and safety to adults aged 40 to 59. About 997 healthy participants will receive one dose of the Butantan dengue vaccine. The goal is to see if the vaccine works as well in older adults as it does in younger adults.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Butantan dengue vaccine (live attenuated virus for serotypes 1-4)
- What this could lead to
- If successful, this could show the vaccine is safe and effective for older adults, expanding protection against dengue to a vulnerable age group.
- What could go wrong
- This is a non-inferiority trial comparing age groups, not a final efficacy study. The vaccine may not work as well in older adults, and side effects could differ.
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 3
Large-scale testing in a bigger group. Usually the last step before a treatment can be approved.
- Participants
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About 997 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Mar 2026
- Expected to finish
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Oct 2027
An estimate. End dates often move.
- Lead sponsor
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A government agency
The lead sponsor is a government body.
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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40 to 79 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: * a. Healthy participants aged between 40 and 79 years at the time of study entry, with or without a history of exposure to dengue fever; b. Agree to periodic contact by telephone, electronic means, and home visits and to the research center; c. Participants with reproductive potential must be using some effective contraceptive method at screening and continue using it for up to 90 days after the intervention; except in cases where the volunteer declares that she is not at risk of becoming pregnant, either by not engaging in sexual activities or by engaging in them in a non-reproductive manner, up to 90 days after vaccination; d. Demonstrate intent to participate in the study, documented by the participant's signature of the informed consent form, as well as the study procedures, including completing the Participant Diaries, blood collection, and being available for scheduled study visits and contacts. Exclusion Criteria: * a. For female participants with reproductive potential: pregnancy (confirmed by positive β-hCG test), breastfeeding or manifest intention to have sexual practices with reproductive potential without using a contraceptive method in the 90 days following vaccination; b. Planned donation of blood, semen or eggs in the 90 days following vaccination; c. Evidence of active uncontrolled neurological, cardiac, pulmonary, hepatic or renal disease according to anamnesis or physical examination, at the discretion of the investigator; d. Diseases that compromise the immune system, including: decompensated diabetes mellitus, active neoplasms or history of neoplasms in the last five years (except basal cell carcinoma), congenital or acquired immunodeficiencies (including HIV/AIDS), solid organ transplants (heart, liver, pancreas, lung, kidney) or uncontrolled autoimmune diseases according to anamnesis or physical examination, as well as a history of liver failure, heart failure or terminal chronic kidney disease or dialysis; e. Behavioral, cognitive, or psychiatric illness that, in the opinion of the principal investigator or his/her medical representative, affects the potential participant's ability to understand and comply with the requirements of the study protocol; f. Any abuse of alcohol or drugs in the last 12 months prior to enrollment in the study that has caused medical, professional, or family problems, as indicated by the clinical history; g. History of severe allergic reaction or anaphylaxis to the vaccine or components of the study vaccine; h. History of asplenia; i. Participation in another clinical trial with administration of an investigational product during the six months prior to enrollment in the study or scheduled participation in another clinical trial in the 12 months following enrollment; j. Previous participation in a dengue vaccine evaluation study or previous exposure to dengue vaccine; k. Use of immunosuppressive therapies six months prior to enrollment in the study or their scheduled use in the 12 months following enrollment. The following immunosuppressive therapies will be considered: antineoplastic chemotherapy, radiotherapy, immunosuppressants to induce tolerance to transplants, monoclonal antibody therapy for the treatment of rheumatological diseases, among others; l.Having received an immunosuppressive dose of corticosteroid in the last three months prior to inclusion in the study or administration of an immunosuppressive dose of corticosteroid for the 12 months following inclusion in the study. The dose of corticosteroid considered immunosuppressive is the equivalent of prednisone at a dose of 20 mg/day, for adults, for 14 days (cumulative dose equivalent to at least 280 mg of prednisone). Continuous use of topical or nasal corticosteroid is not considered immunosuppressive; m. Having received blood products (transfusions or immunoglobulins) in the last three months prior to inclusion in the study, or scheduled administration of blood products or immunoglobulin in the 12 months following inclusion in the study; n. Fever, suspected or measured, in the 72 hours prior to vaccination or axillary temperature ≥ 37.8°C on the day of vaccination (inclusion may be postponed until the potential participant has been fever-free for 72 hours); o. Having received a live attenuated virus vaccine in the last 28 days or an inactivated vaccine in the last 14 days prior to inclusion in the study, or having been immunized within 12 months of inclusion in the study; p. Any other condition that, in the opinion of the principal investigator or his/her medical representative, may jeopardize the safety or rights of a potential participant or that prevents him/her from complying with this protocol.
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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
5 sites. 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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CWB 02 - Centro Médico São Francisco
RECRUITINGCuritiba, Paraná, 80810-050, Brazil
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PET 01 - Hospital Escola da Universidade de Pelotas - HEUFPEL
RECRUITINGPelotas, Rio Grande do Sul, 96040-010, Brazil
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POA 01 - Centro de Pesquisa: Hospital São Lucas - PUCRS
RECRUITINGPorto Alegre, Rio Grande do Sul, 90610-000, Brazil
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POA 02 - Associação Hospitalar Moinhos de Vento
RECRUITINGPorto Alegre, Rio Grande do Sul, 90560-032, Brazil
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POA 05 - Núcleo de Pesquisa do Rio Grande do Sul
RECRUITINGPorto Alegre, Rio Grande do Sul, 90430-001, Brazil
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Other studies related to the condition(s) this trial covers.
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- Can a digital assistant help clinics catch dengue fever faster?
- Can detailed tracking of dengue patients sharpen the next generation of clinical trials?
- Scientists deliberately infect volunteers with dengue to unlock immune secrets