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Recruiting

NCT Number: NCT07135453

Induction of Cross-protective Antibodies for Serogroup 33 by Pneumococcal Conjugate Vaccines

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.

Recruiting

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Key information

Conditions

Vaccine Bacterial Infections Bacterial Infections and Mycoses Gram-Positive Bacterial Infections Infections Pneumococcal Disease Pneumococcal Infections Streptococcal Infections

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of Alabama at Birmingham

Birmingham, Alabama, 35294, United States

Location status: Recruiting

Location contact

David C LaFon, MD

PRINCIPAL_INVESTIGATOR

LaFon, MD

CONTACT

[email protected]

2059343411

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy adult

Exclusion criteria

  • No prior history of pneumococcal vaccination
  • No immunosuppressing medications or chronic diseases that affect immune function

Treatment and study plan

Pneumococcal vaccine

Biological

PCV

Primary outcomes

  1. Serogroup 33 antibodies

    Time frame: 4 weeks post-vaccination

    Serum antipneumococcal antibody concentrations (micrograms/mL) against members of serogroup 33, measured using WHO-ELISA

  2. 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.

Study contacts

Contact information is provided by the study sponsor or research team.

David LaFon, MD

CONTACT

[email protected]

2059343411

Sponsors and collaborators

Lead sponsor

University of Alabama at Birmingham

Other

Collaborators

  • Merck Sharp & Dohme LLC

Registry information

Official study title

Novel Serotype Alert: Investigate New Pneumococcal Conjugate Vaccines for Inducing Cross-protection Against Newly Discovered Serotype 33E and Putative Novel Serogroup 33 Serotypes

Acronym: Group 33/PCVs

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Aug 22, 2025
Registry last updated
Jul 9, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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