Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruiting

Study on the Safety and Immune Response of a High-Dose Influenza Vaccine in Adults Aged 60 and Over, Comparing Trivalent Influenza Vaccine with a Drug Combination

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 effectiveness and safety of a new high-dose vaccine for influenza, commonly known as the flu, in adults aged 60 and older. The study will compare Abbott's candidate high-dose vaccine, known as Trivalent Influenza Vaccine - High Dose (TIV-HD), with an existing vaccine called Efluelda. Both vaccines are designed to protect against three different strains of the influenza virus, which are updated regularly to match the most common strains circulating each flu season.

The purpose of the study is to determine if the new high-dose vaccine is at least as effective as the existing vaccine in producing an immune response. Participants will receive either the new vaccine or the existing one through an injection. The study will monitor the immune response by measuring specific antibodies in the blood 28 days after vaccination. Participants will also be observed for any side effects or adverse reactions following the vaccination.

The study will take place over several months, with participants being followed up to six months after receiving the vaccine. This will help researchers gather comprehensive data on the vaccine's safety and its ability to trigger a strong immune response. The ultimate goal is to ensure that the new high-dose vaccine provides effective protection against influenza in older adults, who are at higher risk for complications from the flu.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial vaccination

    Upon joining the study, you will receive your first dose of the high-dose influenza vaccine. This vaccine is designed to help your body build protection against the flu.

    The vaccine will be given as an intramuscular injection, which means it will be injected into a muscle, usually in your upper arm.

    After receiving the vaccine, you will be asked to stay for a short period to ensure there are no immediate reactions.

  2. Step 2

    Recording reactions

    For the first 7 days after your vaccination, you will need to record any reactions you experience. This includes reactions at the injection site, such as redness or swelling, and general reactions like fever or headache.

    You will use an application on your personal device, such as a smartphone or tablet, to record these reactions. If you do not have a device, one will be provided to you.

  3. Step 3

    Follow-up visit

    28 days after your first vaccination, you will return for a follow-up visit. During this visit, your health will be assessed, and any reactions you recorded will be reviewed.

    This visit is important to ensure your safety and to gather information on how well the vaccine is working.

  4. Step 4

    Revaccination

    At the follow-up visit, you will receive a second dose of the high-dose influenza vaccine.

    This second dose is given to boost your immune response and provide better protection against the flu.

  5. Step 5

    Second recording period

    After the second vaccination, you will again record any reactions for 7 days using the application on your device.

    This helps in monitoring your response to the second dose and ensures your continued safety.

  6. Step 6

    Long-term follow-up

    You will have additional follow-up visits over the next 6 months. These visits are to monitor your health and any long-term effects of the vaccine.

    During these visits, you will be asked about any health changes and may undergo some routine health checks.

Who can join the trial?

4 criteria

  • Willing and able to give informed consent, which means you understand the study and agree to participate.
  • Adults who are 60 years of age or older and are generally healthy, as judged by the study doctor based on your medical history and a health check-up. You can have other health conditions as long as they are under control. If you take regular medication, the dose must not have changed in the last 3 months before getting the study vaccine.
  • If you are a female participant, you must be postmenopausal. This means you have not had a menstrual period for at least 1 year, or you have hormone levels that show your ovaries are not active.
  • Able to follow the study requirements, including using an app on a personal device like a smartphone or tablet to record any events or information needed for the study.

Who cannot join the trial?

3 criteria

  • Participants must be at least 60 years old.
  • Both men and women can participate.
  • Participants should not belong to any vulnerable population. This means groups of people who might be at a higher risk of harm or exploitation, such as those with certain disabilities or those who cannot make decisions for themselves.
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

Trial locations

Where you can join this trial

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

Not 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

  • Abbott’s Candidate High-Dose Influenza Vaccine

    is a new vaccine being tested to see how well it works in people aged 60 and older. This vaccine is designed to protect against the flu by helping the body build up defenses, known as antibodies, against the virus. The study is checking if this new vaccine can create a strong immune response, similar to or better than another flu vaccine already in use.

  • Efluelda®

    is an existing flu vaccine used as a comparison in this study. It is given to people to help protect them from getting the flu by boosting their immune system. The study is comparing the immune response generated by Efluelda® to that of the new vaccine being tested, to see if the new vaccine is just as effective or better at preventing the flu.

What is already known about the treatment

Abbott's Candidate High-Dose Influenza Vaccine – This vaccine is administered as an injection, typically into the muscle of the upper arm. It is currently being studied in clinical trials to assess its safety and effectiveness in people aged 60 and older. The main purpose of this vaccine is to protect against influenza, commonly known as the flu. It works by stimulating the body's immune system to produce antibodies that can recognize and fight the flu virus. This vaccine is classified as a high-dose trivalent influenza vaccine, meaning it targets three different strains of the flu virus.

Investigated diseases

Influenza – Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It primarily affects the nose, throat, and sometimes the lungs. The disease typically begins suddenly and is characterized by symptoms such as fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue. In some cases, it can lead to more severe complications, especially in older adults, young children, and individuals with certain health conditions. The virus spreads mainly through droplets made when people with the flu cough, sneeze, or talk. The progression of the disease can vary, with symptoms lasting from a few days to less than two weeks.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-519743-15-00Protocol codeINFQ-324-0476Estimated enrolment1 283 patientsSponsorAbbott Biologicals B.V.

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

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.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).