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RecruitingAccepts healthy volunteersPhase 3

A Study to Assess the Safety, Tolerability, and Immunogenicity of 3 Lots of a Multivalent Pneumococcal Conjugate Vaccine Administered to Adults

Pfizer · NCT07794748

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Opens the official ClinicalTrials.gov record, with the study team’s contacts. Bored Studies doesn’t enroll anyone.

Key facts

Compensation
Not posted. Ask the study team before screening.
Who can join
Ages 18–49 · All sexes
Healthy volunteers
Accepted
Study type
Interventional · Phase 3
Target enrollment
4670
US sites recruiting
37
Study start
September 8, 2026
Record last updated
October 14, 2026

Status re-checked against ClinicalTrials.gov within the last 12 hours.

What the study is about

The purpose of this study is to provide safety data and demonstrate lot consistency with the PG4 vaccine by evaluating the immunogenicity of 3 different lots of this vaccine.

This study will compare a new pneumococcal vaccine with the vaccine currently in use to see if they are similarly safe. It will also compare three batches of the new vaccine to make sure they work the same way. Blood samples will be taken to measure how the body responds to the vaccines.

The study will be conducted in the United States. Participants will be assigned to 1 of 4 groups. Group 1: PG4 vaccine lot 1; Group 2: PG4 vaccine lot 2; Group 3: PG4 vaccine lot 3; Group 4: 20vPnC.

Within each group, participants will be assigned by chance in a 2:2:2:1 ratio to receive 1 vaccine injection (shot) with either PG4 (new vaccine) lot 1, PG4 lot 2, PG4 Lot 3 or 20vPnC, given in the arm. This means that for every 7 participants, about 2 will receive either PG4 lot 1, lot 2 or lot 3 and about 1 will receive 20vPnC.

Each participant will take part in the study for approximately 6 months.

Being studied: PG4 Multivalent Vaccine; PG4 Multivalent Vaccine; PG4 Multivalent Vaccine; 20 Valent Pneumococcal Conjugate Vaccine (20vPnC)

Conditions: Pneumococcal Disease

Eligibility criteria

Copied from the official record. The study team makes the final decision at screening.

Show full criteria

Inclusion Criteria

Adults 18 through 49 years of age, who have no history of receiving a pneumococcal vaccine after 5 years of age.

Exclusion Criteria

Individuals with a history of severe allergic reactions to a vaccine or its components, serious chronic medical disorders, significant psychiatric conditions, known or suspected immunodeficiency, substance abuse issues, asplenia, bleeding diathesis or prolonged bleeding, a history of a prior confirmed invasive pneumococcal infection, and pregnant or breastfeeding females will be excluded from enrollment in the trial.

Recruiting US locations

Study contacts (from the official record)

  • Pfizer CT.gov Call Center · 1-800-718-1021 · ClinicalTrials.gov_Inquiries@pfizer.com
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A Study to Assess the Safety, Tolerability, and Immunogenicity of… (NCT07794748) | Bored Studies