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OpenTrials
Active, Not Recruiting

NCT Number: NCT07086677

A Study to Learn About How a New Pneumococcal Vaccine Works in Adults

The purpose of this study is to learn about the safety and tolerability of a pneumococcal vaccine in adults.

Participants will receive either:

* an experimental PG4 vaccine * a PG4 vaccine comparator * a standard 20vPnC vaccine comparator * placebo. A placebo does not have any medicine in it but looks just like the study medicine.

Participants will take part in this study for up to 18 months depending on which group they are assigned to. During this time, the participants will receive up to two doses of study vaccine or comparator and take part in follow-up visits.

At these clinic visits, participants will be asked if any side effects were experienced. The participants will also have to give blood samples during clinic visits.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Streptococcus Pneumoniae

Age range

65 year–84 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Orange County Research Center, Lake Forest, California, United States

Loading trial locations.

Who can participate

Healthy volunteers accepted: Yes

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

Key Inclusion Criteria:

  • Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
  • Participants either with no history of ever receiving a pneumococcal vaccine or who have received a pneumococcal vaccine more than 5 years prior to vaccination in this study

Key Exclusion Criteria:

  • Participants with a history of microbiologically proven invasive disease caused by S pneumoniae.

Treatment and study plan

PG4 vaccine in Buffer 1 with low dose PA-001

Biological

Multivalent pneumococcal conjugate vaccine

PG4 in Buffer 1 with low dose PA-002

Biological

Multivalent pneumococcal conjugate vaccine

PG4 in Buffer 1 with high dose PA-001

Biological

Multivalent pneumococcal conjugate vaccine

PG4 vaccine in Buffer 1 with high dose PA-002

Biological

Multivalent pneumococcal conjugate vaccine

PG4 vaccine in Buffer 2

Biological

Multivalent pneumococcal conjugate vaccine

20-valent pneumococcal conjugate vaccine

Biological

(20vPnC)

Saline injection

Biological

Placebo

Primary outcomes

  1. Percentage of participants reporting prespecified local reactions after each dose.

    Time frame: Within 7 days after each study intervention.

    Prespecified local reactions (redness, swelling, and pain at the injection site) occurring within 7 days of each dose administered in the study.

  2. Percentage of participants reporting prespecified systemic reactions after each dose.

    Time frame: Within 7 days after each study intervention.

    Prespecified systemic reactions (fever, vomiting, diarrhea, headache, fatigue, muscle pain, and joint pain) occurring within 7 days of each dose administered in the study.

  3. Percentage of participants reporting adverse events.

    Time frame: From signing of the ICD to 1 month after last study intervention.

    Adverse Events (AEs) occurring from Dose 1 through 1 month after the last vaccination

  4. Percentage of participants reporting serious adverse events.

    Time frame: From signing of the ICD to 6 months after the last study intervention.

    Serious Adverse Events (SAEs) occurring from Dose 1 through 6 months after the last vaccination.

  5. Percentage of participants reporting serious adverse events.

    Time frame: From signing of the ICD to 12 months after the last study intervention.

    Serious Adverse Events (SAEs) occurring from Dose 1 through 12 months after the last vaccination.

  6. Percentage of participants with abnormal hematology and chemistry laboratory values.

    Time frame: Within 2 weeks after each study intervention.

    Any abnormal hematology or chemistry laboratory values as compared to baseline within 2 weeks after each study intervention.

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Registry information

Official study title

A PHASE 1, RANDOMIZED, DOUBLE-BLIND, SPONSOR-OPEN STUDY TO DESCRIBE THE SAFETY AND TOLERABILITY OF A MULTIVALENT PNEUMOCOCCAL CONJUGATE VACCINE IN ADULTS

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Jul 25, 2025
Registry last updated
Jun 22, 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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