Pneumococcal VaccinesPhase 4NCT06271681
Evaluation of PCV21 Vaccination Among PPSV23-experienced, Immunocompromised Elderly Veterans
A Phase 4 study testing 21-valent pneumococcal conjugate vaccine in people with Pneumococcal Vaccines and Immunosuppression, run by VA Sierra Nevada Health Care System.
Trial summary
The investigators will evaluate the immune response of immunocompromised adults, who have previously received at least 1 dose of 23-valent pneumococcal polysaccharide vaccine, to the booster with of 21-valent pneumococcal conjugate vaccine . Immune response will be assessed by opsonophagocytic assay reactivity. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Pneumococcal Vaccines, Immunosuppression
- What is being tested?
- 21-valent pneumococcal conjugate vaccine
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2026to 1 Jun 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Subject meets the CDC definition of an immunocompromising condition
- o chronic renal failure, congenital or acquired asplenia, generalized malignancy, HIV infection, Hodgkin disease, iatrogenic immunosuppression, leukemia, lymphoma, multiple myeloma, nephrotic syndrome, sickle cell disease or other hemoglobinopathies, and solid organ transplant.
- Have received at least 1 dose of PPSV23
Who cannot join
- Less than 5 years since last receipt of PPSV23 validated to patient medical record and Immunize Nevada Website
- Previous administration of PCV20
- Previous administration of PCV13
- Previous administration of PCV15
- Less than 14 days since administration of any COVID19 vaccination
- Previous history of Invasive Pneumococcal Disease (IPD)
- Antibiotic treatment within the previous 90 days
About this study
The investigators will evaluate the immune response of immunocompromised adults, who have previously received at least 1 dose of 23-valent pneumococcal polysaccharide vaccine, to the booster with of 21-valent pneumococcal conjugate vaccine . Immune response will be assessed by opsonophagocytic assay reactivity.
Read the detailed description
Recommendations for optimal vaccination strategies in immunocompromised patients has been limited. Strategies focused on utilizing a conjugate vaccine alone, as either initial vaccination or booster dosing, have not demonstrated significant increased antibody expression in immunocompromised patients[7]. Strategies where immunocompromised patients were vaccinated with a conjugate vaccine followed by polysaccharide vaccine have demonstrated that 50% of individuals achieve functional antibodies[7]. Since improved antibody response in naive patients has been seen in combination vaccination, we aim to test this strategy for boosting in previously vaccinated immunocompromised patients. The 15 valent Pneumococcal Conjugate Vaccine (PCV15) is available for use in adults and contains S. Pneumoniae serotypes 1, 3, 4, 6A, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F [5].
In this study we postulate that booster dosing with PCV21 in immunocompromised adults who are at least 5 years from receipt of PPSV23 will elicit a strong immune response represented by change in serotype specific OPA GMT from baseline to 4 weeks post booster vaccine completion. We will specifically evaluate the change in pneumococcal opsonophagocytic activity at baseline to 6 months (Pn-OPA) for S. Pneumoniae serotypes 3, 6A, 15A, 19A, 20A, 23A, 31, 35B, 9n, 11A, and 22F. These specific serotypes have been selected due to current disease burden trends, to address current gaps in data, and have been identified as the most relevant for PCV development underway.
- Conditions
- Pneumococcal Vaccines, Immunosuppression
- Being tested
- 21-valent pneumococcal conjugate vaccine
- Keywords
- immunosuppression, pneumococcal vaccines
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
21-valent pneumococcal conjugate vaccineDrug
Also called PCV21
FDA approved pneumococcal vaccines 21 valent conjugate vaccine administered at enrollment
| Study group | Role | What they receive |
|---|---|---|
| All participants | Other | This will be a single population open label trial evaluating immune response to PCV21 in subjects with immunocompromising conditions or receiving immunosuppressive medications. Receives: Drug: 21-valent pneumococcal conjugate vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in opsonophagocytic assay (OPA) geometric mean titers (GMT)
Evaluation of the change fold increase in S. Pneumonia OPA GMT from baseline to 24 weeks after the administration of a pneumococcal vaccine booster series consisting of PCV15 followed by PPSV23 8 weeks later for S. Pneumoniae serotypes 1, 3, 4, 6A, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F
Measured: 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Feb 2024
- Study start1 Jan 2026 (estimated)
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Pneumococcal VaccinesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- VA Sierra Nevada Health Care System
- Sponsor type
- US federal agency
- Collaborators
- Merck Sharp & Dohme LLC
- Responsible party
- Principal investigator, Amneet Rai, VA Sierra Nevada Health Care System
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06271681
- Sponsor's protocol ID
- 2120135-1
- Status last verified
- Aug 2025
- First submitted
- 4 Jan 2024
- Last updated
- 14 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data is not planned to be made available at this time.
Study at a glance
From the registry record, last updated by the sponsor on 14 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of PCV21 Vaccination Among PPSV23-experienced, Immunocompromised Elderly Veterans
- ClinicalTrials.gov ID
- NCT06271681
- Acronym / sponsor ID
- 2120135-1
- Conditions
- Pneumococcal Vaccines, Immunosuppression
- Keywords
- immunosuppression, pneumococcal vaccines
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- VA Sierra Nevada Health Care SystemUS federal agency
- Collaborators
- Merck Sharp & Dohme LLC
- Study start
- 1 Jan 2026 (estimated)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jun 2027 (estimated)
- First posted
- 22 Feb 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The investigators will evaluate the immune response of immunocompromised adults, who have previously received at least 1 dose of 23-valent pneumococcal polysaccharide vaccine, to the booster with of 21-valent pneumococcal conjugate vaccine . Immune response will be assessed by opsonophagocytic assay reactivity.
Detailed description
Recommendations for optimal vaccination strategies in immunocompromised patients has been limited. Strategies focused on utilizing a conjugate vaccine alone, as either initial vaccination or booster dosing, have not demonstrated significant increased antibody expression in immunocompromised patients[7]. Strategies where immunocompromised patients were vaccinated with a conjugate vaccine followed by polysaccharide vaccine have demonstrated that 50% of individuals achieve functional antibodies[7]. Since improved antibody response in naive patients has been seen in combination vaccination, we aim to test this strategy for boosting in previously vaccinated immunocompromised patients. The 15 valent Pneumococcal Conjugate Vaccine (PCV15) is available for use in adults and contains S. Pneumoniae serotypes 1, 3, 4, 6A, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F [5].
In this study we postulate that booster dosing with PCV21 in immunocompromised adults who are at least 5 years from receipt of PPSV23 will elicit a strong immune response represented by change in serotype specific OPA GMT from baseline to 4 weeks post booster vaccine completion. We will specifically evaluate the change in pneumococcal opsonophagocytic activity at baseline to 6 months (Pn-OPA) for S. Pneumoniae serotypes 3, 6A, 15A, 19A, 20A, 23A, 31, 35B, 9n, 11A, and 22F. These specific serotypes have been selected due to current disease burden trends, to address current gaps in data, and have been identified as the most relevant for PCV development underway.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| All participants | Other | Drug: 21-valent pneumococcal conjugate vaccineThis will be a single population open label trial evaluating immune response to PCV21 in subjects with immunocompromising conditions or receiving immunosuppressive medications. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- Subject meets the CDC definition of an immunocompromising condition
- o chronic renal failure, congenital or acquired asplenia, generalized malignancy, HIV infection, Hodgkin disease, iatrogenic immunosuppression, leukemia, lymphoma, multiple myeloma, nephrotic syndrome, sickle cell disease or other hemoglobinopathies, and solid organ transplant.
- Have received at least 1 dose of PPSV23
Key exclusion criteria (7 listed)
- Less than 5 years since last receipt of PPSV23 validated to patient medical record and Immunize Nevada Website
- Previous administration of PCV20
- Previous administration of PCV13
- Previous administration of PCV15
- Less than 14 days since administration of any COVID19 vaccination
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 21-valent pneumococcal conjugate vaccineAlso: PCV21FDA approved pneumococcal vaccines 21 valent conjugate vaccine administered at enrollment | Drug | All participants |
Primary outcome
Change in opsonophagocytic assay (OPA) geometric mean titers (GMT)
Time frame: 24 months
Evaluation of the change fold increase in S. Pneumonia OPA GMT from baseline to 24 weeks after the administration of a pneumococcal vaccine booster series consisting of PCV15 followed by PPSV23 8 weeks later for S. Pneumoniae serotypes 1, 3, 4, 6A, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F and 33F
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Aug 2025.
- Individual participant dataSharing planned: No. Individual participant data is not planned to be made available at this time.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing 21-valent pneumococcal conjugate vaccine in people with Pneumococcal Vaccines and Immunosuppression, run by VA Sierra Nevada Health Care System.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 14 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in opsonophagocytic assay (OPA) geometric mean titers (GMT) (time frame: 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2025; AzTrials last refreshed its copy on 7 Nov 2026.