Helsinki University Central Hospital
Helsinki, Finland
Not yet recruiting
Study on Immune Response to Intradermal Ixiaro Vaccine in Healthy Adults Aged 18-64
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What is this trial about?
A plain-language summary of the goals, design and what participants do
This clinical trial is focused on studying the immune response to the IXIARO vaccine, which is used to protect against Japanese encephalitis. Japanese encephalitis is a viral infection that affects the brain and is transmitted through mosquito bites. The study involves healthy adults aged 18 to 64 who have not previously received a Japanese encephalitis vaccination. The purpose of the study is to determine if administering the vaccine into the skin (intradermally) is as effective as the traditional method of injecting it into the muscle (intramuscularly).
Participants in the study will receive a single dose of the IXIARO vaccine. The study will compare the immune response generated by the two different methods of administration by measuring the levels of neutralizing antibodies in the blood. Antibodies are proteins produced by the immune system to help fight infections. The study will also look at other aspects of the immune response, such as the presence of certain immune cells and any side effects experienced by participants.
The trial aims to provide valuable information on whether the intradermal method of administering the IXIARO vaccine can be a viable alternative to the intramuscular method. This could potentially offer a more efficient way to deliver the vaccine, especially in areas where Japanese encephalitis is common. The study is expected to continue until the end of 2029, with the goal of improving vaccination strategies against this serious disease.
The research process
The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.
Who can join the trial?
6 criteria
- Participants must be 18 to 64 years old.
- Participants should be in general good health, which will be checked through their medical history and a physical examination.
- Participants need to provide written informed consent, which means they agree to take part in the study after understanding what it involves.
- Females of childbearing potential must agree to use a reliable method of birth control during the study. This can be a hormonal method (like birth control pills) or a barrier method (like condoms). Choosing not to have sex (abstinence) is also acceptable.
- Participants must be available for all scheduled visits during the study.
- Participants must have no previous vaccination for Japanese encephalitis.
Who cannot join the trial?
3 criteria
- Individuals who are not between the ages of 18 and 64.
- Individuals who do not have general good health.
- Individuals who are part of a vulnerable population. This means groups of people who might need special protection or care, such as those with certain disabilities or conditions.
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Investigated drugs
Ixiaro is a vaccine used to protect against Japanese encephalitis, a viral infection that can cause inflammation of the brain. In this clinical trial, the vaccine is being tested to see if it can be given in a different way, specifically through the skin (intradermally), rather than the usual method of injection into the muscle (intramuscularly). The goal is to determine if this new method of administration can produce a similar immune response, which is measured by the level of protective antibodies in the blood. This could potentially make the vaccination process easier and more comfortable for patients.
What is already known about the treatment
Ixiaro – Ixiaro is a vaccine administered through the skin (intradermally) to healthy adults aged 18-64, aiming to protect against Japanese encephalitis. It is currently being studied to see if a single intradermal dose can produce an immune response that is as strong as the traditional method of injecting it into the muscle (intramuscularly). The vaccine works by stimulating the body's immune system to produce antibodies that can neutralize the virus, thereby preventing infection. Ixiaro is classified as a vaccine, which is a type of medicine designed to prevent diseases by enhancing the body's natural defenses.
Investigated diseases
Japanese Encephalitis – Japanese Encephalitis is a viral infection that affects the brain. It is caused by the Japanese Encephalitis virus, which is transmitted through mosquito bites. The disease often begins with symptoms such as fever, headache, and vomiting. As it progresses, it can lead to swelling of the brain, resulting in confusion, seizures, or movement disorders. In some cases, individuals may experience stiffness in the neck or become unresponsive. The progression of the disease can vary, with some individuals recovering fully while others may experience long-term neurological issues.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-519876-17-00Protocol codeIxiaro i.d. - IdIxEstimated enrolment240 patientsSponsorHUS-yhtymae
sourced from the EU Clinical Trials Register and site verification
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