AuthorisedTherapeutic use (Phase IV)Interventional

Immune response to intradermally administered Ixiaro in healthy adults

This study is investigating a vaccine called Ixiaro, which protects against Japanese encephalitis. We want to see how the body responds when the vaccine is given just under the skin (intradermal) compared to the usual way, into a muscle. Specifically, researchers will measure how many protective antibodies the body makes after vaccination. They will also look at other immune cells and any side effects people experience. This research is for healthy adults between 18 and 64 years old and is part of understanding the best way to use this important vaccine.

At a glance

Status

Authorised

Phase

Therapeutic use (Phase IV)

Sponsor

HUS-Yhtymae

Enrolment target

240

Start

10 Jan 2025

18-64 years old volunteers with general good health

What is this study about?

This research study is looking at a vaccine called Ixiaro, which helps protect people from Japanese encephalitis. This illness is caused by a virus found in some parts of Asia and can be very serious. The main goal of this study is to find out how well your body creates protection (called an 'immune response') when the vaccine is given in different ways.

Usually, vaccines are given into the muscle. But this study wants to see if giving the Ixiaro vaccine just under the skin (a method called 'intradermal') works as well, or even better, at getting your body to produce protective cells. Scientists will carefully measure the levels of special protective substances, called antibodies, in your blood. These antibodies are key to fighting off the virus if you were ever exposed to it.

Beyond just checking antibody levels, the study will also look at other parts of your immune system. Researchers will compare how different vaccination methods affect certain immune cells. They will also keep a close eye on any reactions or side effects participants might have. This information is important for doctors to understand the best and safest way to give this vaccine in the future.

Key takeaways

Tests a Japanese encephalitis vaccine (Ixiaro).
Compares giving the vaccine into the skin vs. into a muscle.
Aims to understand the body's immune response.
Looks for any side effects.
For healthy adults aged 18-64.
Could help improve future vaccination methods.

Who may be eligible?

To be considered for this study, you need to be a healthy adult aged 18 to 64 years old. This means you should generally feel well and not have any major ongoing health problems that could affect the study results or your safety.

The study is open to both men and women. We need volunteers from all backgrounds to make sure the results apply to a wide range of people.

Before you can join, the study team will carefully check your health to make sure it's safe for you to take part and that you meet all the specific requirements of the study.

Quick self-check

Are you between 18 and 64 years old?
Do you consider yourself generally healthy?
Are you able to attend clinic appointments?
Are you comfortable with blood tests and injections?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you decide to take part, you will receive the Ixiaro vaccine. The study team will explain whether you will get the vaccine into a muscle or just under the skin. You will need to attend several appointments at the study clinic. At these visits, doctors will take small blood samples to measure your immune response. They will also ask you how you are feeling and if you have experienced any side effects. You will be asked to keep a record of any symptoms you notice at home. The total time you will be involved in the study will be explained to you before you agree to join.

Potential risks and benefits

Taking part in this study could help us learn more about the most effective way to protect against Japanese encephalitis, potentially benefiting others in the future. As with any vaccine, there's a chance you might experience common side effects like soreness, redness, or swelling where the injection was given, or mild flu-like symptoms. More serious side effects are rare. You have the right to leave the study at any time, for any reason, without it affecting your medical care.

Locations (1)

—
Finland

Common questions

What is Japanese encephalitis?

Japanese encephalitis is a serious brain infection caused by a virus, usually spread by mosquitoes, found in parts of Asia. It can cause long-term health problems or even be life-threatening.

What does a 'vaccine' do?

A vaccine helps your body learn to fight off certain diseases without you actually getting sick. It teaches your immune system to recognise and destroy harmful viruses or bacteria.

What's the difference between 'intradermal' and 'intramuscular'?

Intradermal means the injection is given just under the top layer of skin, usually with a smaller needle. Intramuscular means the injection goes deeper, into a muscle, which is how most common vaccines are given.

Will I know my results?

The study team won't be able to share individual detailed results immediately. However, once the study is finished, the overall findings will likely be published and made available.

Do I get paid to take part?

The study team will be able to tell you if there is any compensation for your time or help with travel costs. This varies from study to study.