Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Recruiting

Study of Pneumococcal Vaccine Response in Patients Without a Spleen: Comparing Vaccination Before and After Spleen Removal Using PCV20 and PCV21

Fast replyRegistered drugNo placebo
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 studies immune responses to pneumococcal vaccines in people without a spleen (a condition called asplenia). The study compares two vaccines: Prevenar 20 and CAPVAXIVE, which are designed to protect against different strains of bacteria that can cause serious infections. The purpose is to understand how the timing of vaccination - either before or after surgical removal of the spleen - affects the body's immune response to these vaccines.

The study involves adults who either have already had their spleen removed or are scheduled for spleen removal surgery. Participants will receive two different vaccines: first Prevenar 20, followed by CAPVAXIVE at least 12 months later. Both vaccines are given as a single injection into the muscle. The main focus is on measuring how well the immune system responds to the vaccines when given at different times relative to spleen removal.

The research team will collect blood samples to measure antibody levels and immune cell responses at various points during the study. This will help determine the best timing for vaccination in patients without a spleen. The study will continue for approximately two years, comparing immune responses between patients vaccinated before spleen removal, after spleen removal, and healthy individuals who still have their spleen.

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

    You will receive the first vaccine called Prevenar 20 as an injection in your muscle

    This vaccine contains substances that help protect against 20 different types of pneumococcal bacteria

    The injection will be given using a pre-filled syringe

  2. Step 2

    First follow-up

    After 3 weeks from your first vaccination, you will have a blood test to measure your body's response to the vaccine

  3. Step 3

    Monitoring period

    A period of at least 12 months will pass while your body's response to the vaccine is monitored

    During this time, blood tests will be taken to measure the lasting effects of the vaccine

  4. Step 4

    Booster vaccination

    After the monitoring period, you will receive a second different vaccine called CAPVAXIVE

    This vaccine protects against 21 types of pneumococcal bacteria

    The injection will be given in your muscle using a pre-filled syringe

  5. Step 5

    Final follow-up

    2-3 weeks after the second vaccine, you will have a final blood test

    This test will measure how your body responded to both vaccines

    Additional blood tests may be conducted up to 12 months after this second vaccine

  6. Step 6

    Study completion

    The study will end after all follow-up tests are completed

    The total duration of your participation will be approximately 24 months

Who can join the trial?

6 criteria

  • Must be aged 18 years or older
  • Must be scheduled for splenectomy (surgical removal of the spleen) due to one of these conditions: - Pancreatic cancer or precancerous pancreatic lesions requiring pancreatic surgery - Blood disorders such as thalassemia (inherited blood disorder affecting hemoglobin production) or sickle cell disease (inherited condition affecting red blood cells)
  • Must have already had a splenectomy for one of the conditions mentioned above
  • Must not have received any pneumococcal conjugate vaccines (PCVs) before, except for PCV20 (a vaccine that helps protect against certain types of bacterial infections)
  • Must be willing and able to provide signed informed consent to participate in the study
  • Can be either male or female

Who cannot join the trial?

14 criteria

  • Age below 18 years or above 65 years
  • Previous allergic reactions to any pneumococcal vaccines (vaccines that protect against bacteria causing pneumonia)
  • Currently having an active infection or fever above 38°C (100.4°F)
  • Received any vaccination in the past 30 days
  • Having a weakened immune system due to medications or medical conditions
  • Pregnancy or breastfeeding
  • Currently participating in other clinical trials
  • History of severe allergic reactions to any vaccine components
  • Having received blood products or immunoglobulins (antibody preparations) in the past 3 months
  • Unable to complete the full study schedule
  • Any condition that, in the opinion of the study doctor, makes participation unsafe
  • Taking medications that affect the immune system
  • History of serious chronic illness that is not well-controlled
  • Unable to provide informed consent
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.

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

  • PCV20

    is a pneumococcal conjugate vaccine that helps protect against 20 different types of pneumococcal bacteria. This vaccine is designed to stimulate the immune system to create antibodies that can fight against pneumococcal infections. It is commonly used as a primary vaccination to prevent diseases like pneumonia and meningitis.

  • PCV21

    is a pneumococcal conjugate vaccine that provides protection against 21 strains of pneumococcal bacteria. This vaccine is used as a booster shot to enhance and maintain the immune response initially created by PCV20. It helps strengthen the body's defense against pneumococcal diseases.

What is already known about the treatment

  • PCV20 (Prevnar 20)

    A pneumococcal conjugate vaccine administered through intramuscular injection, designed to protect against 20 different strains of Streptococcus pneumoniae bacteria. This vaccine is currently approved for use in adults and has shown significant effectiveness in preventing pneumococcal disease, particularly in individuals with compromised immune systems or those without a spleen. It works by stimulating the immune system to produce antibodies against specific pneumococcal serotypes, helping the body recognize and fight these bacteria more effectively.

  • PCV21

    An investigational pneumococcal conjugate vaccine administered via intramuscular injection, which includes coverage for 21 serotypes of Streptococcus pneumoniae. This vaccine is currently being studied in clinical trials as a booster vaccination, particularly in patients who have previously received PCV20. The vaccine stimulates B-cell immune response to create antibodies against pneumococcal bacteria, with special focus on evaluating its effectiveness in patients who have undergone splenectomy.

Investigated diseases

Asplenia - A condition characterized by the absence of a functioning spleen, which can be congenital (present at birth) or acquired (due to surgical removal of the spleen). The spleen is an organ that plays a crucial role in the body's immune system and helps filter blood. In asplenia, the body has reduced ability to fight certain types of infections. The condition affects the body's capacity to remove old or damaged blood cells from circulation. People with asplenia may have altered immune responses and changes in blood cell composition.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-515363-63-00Protocol code2024-515363-63-00Estimated enrolment70 patientsSponsorLeids Universitair Medisch Centrum (LUMC)

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.