Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruiting

Study on the Effectiveness of dTap Vaccine in Boosting Immunity Against Diphtheria, Tetanus, and Whooping Cough in Healthcare Workers

Registered 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 immune response to a booster vaccination in healthcare workers. The diseases being studied are diphtheria, tetanus, and pertussis (commonly known as whooping cough). The treatment used in this study is a vaccine called dTap, which is designed to boost immunity against these diseases. The vaccine contains several components, including diphtheria toxoid, tetanus toxoid, and various parts of the pertussis bacteria that help the body recognize and fight the infection.

The purpose of the study is to understand how the immune system of healthcare workers responds to the dTap booster vaccine. Participants will receive the vaccine and their immune response will be measured before and after vaccination. The study will involve two visits where participants will complete questionnaires and provide blood samples. These samples will help researchers measure the levels of specific antibodies, which are proteins made by the immune system to fight infections, and other immune responses.

The study will track changes in the immune system over a period of four weeks after the booster vaccination. This includes measuring the levels of antibodies specific to pertussis, as well as the immune response to diphtheria and tetanus. The results will help determine how well the vaccine works in boosting immunity among healthcare workers who are regularly in contact with infants, a group particularly vulnerable to these diseases.

The research process

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

  1. Step 1

    Initial visit

    Upon joining the study, you will attend an initial visit. During this visit, you will complete a questionnaire about your health and work environment.

    A blood sample will be taken to measure your current immunity levels against diphtheria, tetanus, and pertussis (whooping cough).

  2. Step 2

    Vaccination

    You will receive a booster vaccination with the dTap vaccine. This vaccine is administered as an intramuscular injection, which means it is given with a needle into a muscle.

    The vaccine contains components to boost your immunity against diphtheria, tetanus, and pertussis.

  3. Step 3

    Post-vaccination period

    After receiving the vaccine, you will have a period of 28 days before the next visit. During this time, your body will develop an immune response to the vaccine.

  4. Step 4

    Follow-up visit

    You will return for a follow-up visit 28 days after the vaccination. During this visit, another blood sample will be taken to assess the immune response generated by the vaccine.

    Additional tests may be conducted to measure specific immune responses, such as antibody levels and other immune cell activities.

Who can join the trial?

4 criteria

  • Must be a healthcare worker who regularly works with infants under 12 months old and needs a **dTap booster vaccination** every 5 years. The dTap vaccine protects against diphtheria, tetanus, and pertussis (whooping cough).
  • It has been more than 4 years since the last **dTap vaccination**.
  • Willing to follow the study procedures, which include attending 2 visits, completing questionnaires, providing blood and MLF samples, and planning to receive the dTap vaccine.
  • Both **male and female** participants are eligible.

Who cannot join the trial?

8 criteria

  • Participants must not have any known allergies to the components of the dTap vaccine. The dTap vaccine is a booster shot for diphtheria, tetanus, and pertussis (whooping cough).
  • Participants should not have received any other vaccines within 4 weeks before the study starts.
  • Participants must not have any serious chronic illnesses. A chronic illness is a long-lasting health condition that requires ongoing medical attention.
  • Participants should not be pregnant or planning to become pregnant during the study period.
  • Participants must not have any immune system disorders. The immune system is the body's defense against infections and illnesses.
  • Participants should not be taking medications that affect the immune system, such as steroids. Steroids are drugs that reduce inflammation and affect the immune system.
  • Participants must not have had a previous severe reaction to any vaccine.
  • Participants should not be participating in another clinical trial at the same time.
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

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

dTap vaccine is a combination vaccine that helps protect against three serious diseases: diphtheria, tetanus, and pertussis (whooping cough). This vaccine is given as a booster to help strengthen the body's defense system, or immunity, against these diseases. In this clinical trial, health care workers receive the dTap vaccine to see how their immune systems respond to it, both before and four weeks after getting the booster shot. The goal is to understand how well the vaccine works in boosting immunity against these diseases in people who work in health care settings.

What is already known about the treatment

dTap vaccine – The dTap vaccine is administered as an injection, typically given in the upper arm. It is currently used in medicine to boost immunity against diphtheria, tetanus, and pertussis (whooping cough), especially in health care workers. The main therapeutic indication is to enhance protection against these diseases by stimulating the body's immune system to recognize and fight the bacteria that cause them. At the molecular level, the vaccine works by introducing inactivated toxins and proteins from the bacteria, prompting the immune system to produce antibodies. It is classified as a combination vaccine, targeting multiple diseases with a single shot.

Investigated diseases

  • Diphtheria

    Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae. It primarily affects the mucous membranes of the throat and nose. The disease begins with a sore throat, fever, and chills. As it progresses, a thick, gray membrane forms in the throat, which can lead to difficulty breathing and swallowing. The bacteria produce a toxin that can spread through the bloodstream, potentially affecting the heart and nerves. Without intervention, the infection can cause severe complications.

  • Tetanus

    Tetanus is a serious bacterial infection caused by Clostridium tetani. The bacteria produce a toxin that affects the nervous system, leading to muscle stiffness and spasms. The disease often starts with muscle stiffness in the jaw, commonly known as lockjaw. As it progresses, the stiffness spreads to other muscles, causing severe muscle spasms and difficulty swallowing. The spasms can be strong enough to cause bone fractures. The bacteria typically enter the body through wounds or cuts.

  • Pertussis (Whooping Cough)

    Pertussis, also known as whooping cough, is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis. It starts with symptoms similar to a common cold, such as a runny nose, mild cough, and fever. As the disease progresses, severe coughing fits develop, which can be followed by a high-pitched "whoop" sound when breathing in. The coughing fits can lead to vomiting and exhaustion. The disease is particularly dangerous for infants and can lead to complications such as pneumonia. The bacteria spread through respiratory droplets from coughing or sneezing.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-511478-56-00Estimated enrolment100 patientsSponsorVarsinais-Suomen hyvinvointialue

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).