Recruiting

Study on the Effects of the Dengue Vaccine Qdenga on Antibody Levels in Swedish Travelers

Fast replyRegistered drug

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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 effects of a vaccine called Qdenga, which is used to prevent dengue fever. Dengue fever is a disease caused by a virus transmitted through mosquito bites, and it can lead to symptoms like high fever, severe headache, and joint pain. The Qdenga vaccine is a live, attenuated vaccine, meaning it contains a weakened form of the virus that helps the body build immunity without causing the disease.

The purpose of this study is to understand how the Qdenga vaccine affects the levels of certain antibodies in the blood. Antibodies are proteins made by the immune system to help fight infections. Specifically, the study will look at whether the vaccine causes increased levels of antibodies that might react with other viruses similar to dengue, such as the viruses that cause tick-borne encephalitis (TBEV), yellow fever (YFV), Zika (ZIKV), and Japanese encephalitis (JE). This will be assessed by comparing antibody levels before and 90 days after receiving two doses of the vaccine.

Participants in the study will receive two doses of the Qdenga vaccine. The study will monitor the participants over a period to observe any changes in antibody levels. This research aims to provide valuable information on how the vaccine interacts with the immune system, particularly in people who may travel to areas where dengue fever is common. The study is expected to continue until 2027.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Initial vaccination
Upon joining the study, you will receive the first dose of the Qdenga vaccine. This vaccine is a live, attenuated vaccine designed to protect against dengue fever. It is administered as a subcutaneous injection, which means it is injected under the skin.
The purpose of this vaccine is to help your body develop immunity against dengue fever, especially if you are planning to travel to areas where dengue is common.
Step 2
Second vaccination
You will receive a second dose of the Qdenga vaccine at a later date. This second dose is important to ensure that your body builds a strong immune response.
The second dose is also given as a subcutaneous injection. The timing of this dose will be communicated to you by the study team.
Step 3
Monitoring and follow-up
After receiving both doses of the vaccine, your antibody levels will be monitored. This involves taking blood samples to measure the levels of IgG antibodies in your blood. These antibodies help determine how well your body is responding to the vaccine.
The primary focus is to assess the levels of antibodies against other viruses like TBEV, YFV, ZIKV, and JE at day 90 after the second dose compared to before vaccination.
Step 4
Completion of study
The study is expected to conclude by November 1, 2027. By this time, all necessary data will have been collected, and your participation in the study will be complete.
You will be informed about the results and any findings related to your participation in the study.

Who can join the trial?

5 criteria

Able to participate in all parts of the study
Signed written informed consent
18 years of age or older
Negative pregnancy test (urine HCG) for women of childbearing potential. HCG is a hormone that is tested to confirm pregnancy.
Planning to travel to a country where dengue fever is common. The decision to get vaccinated will be made together with your doctor, following guidelines from the Swedish Society for Infectious Diseases Physicians.

Who cannot join the trial?

10 criteria

Participants must not have any serious health conditions that could interfere with the study.
Participants should not have received any other vaccines within a certain period before the study starts.
Participants must not have a history of severe allergic reactions to any component of the vaccine.
Participants should not be pregnant or planning to become pregnant during the study period.
Participants must not be breastfeeding during the study.
Participants should not have any immune system disorders, which means their body's defense system is not working properly.
Participants must not be taking medications that affect the immune system, such as steroids.
Participants should not have participated in another clinical trial recently.
Participants must not have a history of drug or alcohol abuse.
Participants should not have any other condition that, in the opinion of the study doctor, makes them unsuitable for the study.

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Responsive
Region Vaesterbotten
Umea, Sweden

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting

Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Qdenga is a vaccine designed to protect against dengue fever, a disease caused by the dengue virus, which is transmitted by mosquitoes. The vaccine works by stimulating the body's immune system to produce antibodies that can recognize and fight the dengue virus if the person is exposed to it in the future. In this clinical trial, the focus is on understanding how the Qdenga vaccine might affect the levels of certain antibodies that can also react to other similar viruses, such as those causing tick-borne encephalitis, yellow fever, Zika, and Japanese encephalitis. The trial aims to see if these antibody levels change significantly after receiving the Qdenga vaccine.

What is already known about the treatment

Qdenga – Qdenga is a vaccine administered through an injection to help prevent dengue fever, a disease caused by a virus transmitted by mosquitoes. It is currently being studied in a phase IV clinical trial to understand its effects on the immune system, particularly how it might cause cross-reactive antibody responses to other similar viruses like TBEV, YFV, ZIKV, and JE. The main use of Qdenga is to protect people from getting dengue fever, especially those traveling to areas where the disease is common. It works by stimulating the body's immune system to recognize and fight the dengue virus if exposed in the future. Qdenga is classified as a prophylactic vaccine, meaning it is used to prevent disease rather than treat it.

Investigated diseases

Dengue Fever – Dengue fever is a viral infection transmitted by mosquitoes, primarily the Aedes aegypti species. The disease begins with a sudden high fever, severe headaches, pain behind the eyes, and joint and muscle pain. As it progresses, a rash may appear, and mild bleeding symptoms such as nosebleeds or gum bleeding can occur. The fever typically lasts for 2 to 7 days, after which the patient may experience a drop in temperature and feel better for a short period. However, some individuals may develop more severe symptoms, including severe abdominal pain, persistent vomiting, and difficulty breathing. The disease is caused by one of four related viruses, and infection with one type does not provide immunity against the others.