NCT07135453 · University of Alabama at Birmingham
Induction of Cross-protective Antibodies for Serogroup 33 by Pneumococcal Conjugate Vaccines
(Group 33/PCVs)
What this study is about
The goal of this study is to learn whether different types of vaccines to prevent bacterial infections are able to effectively create antibodies that defend against certain types of bacteria. We will give two different types of vaccine and evaluate the effectiveness of antibodies produced by each vaccine in killing bacteria.
View original scientific description
The goal of this study is to learn whether different types of vaccines to prevent bacterial infections are able to effectively create antibodies that defend against certain types of bacteria. We will give two different types of vaccine and evaluate the effectiveness of antibodies produced by each vaccine in killing bacteria.
Interventions
BIOLOGICAL
Pneumococcal Vaccine
PCV
Primary outcome measures
Serogroup 33 antibodies
Time frame: 4 weeks post-vaccination
Serum antipneumococcal antibody concentrations (micrograms/mL) against members of serogroup 33, measured using WHO-ELISA
Antibody-mediated killing
Time frame: 4 weeks post-vaccination
Opsonic activity of vaccine-induced antibodies (reported as opsonic index, or OI); measured using an opsonophagocytic killing (OPK) assay.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Healthy adult
Exclusion criteria
- No prior history of pneumococcal vaccination
- No immunosuppressing medications or chronic diseases that affect immune function
Where
- Birmingham, Alabama
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 9, 2026 · Source of record for eligibility and locations