Recruiting
Phase 3

RSVpreF

Sponsor:

Pfizer

Code:

NCT07768345

Conditions

Respiratory Syncytial Virus (RSV)

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

RSVpreF Vaccine

Study Details

Brief summary:

The purpose of this phase 3 study is to learn the safety, tolerability and immunogenicity of revaccination with RSVpreF at approximately 1-, 2-, and 3-year intervals to inform the revaccination interval in immunocompromised adults.

This study is seeking participants who are 18 years of age and older and will be grouped based on prior RSV vaccination history. Participants are required to be immunocompromised per study protocol.

All participants in this study will receive 1 shot to their arm of a RSVPreF vaccine.

Participants will take part in this study for about 12 months and will need to visit the clinical study site at least 4 times.

Conditions

Respiratory Syncytial Virus (RSV)

Study ID

NCT07768345

Start date

Aug 31, 2026

Status verified date

Sep, 2026

Completion date

Feb 2, 2028

Anticipated

Primary completion date

Feb 2, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Participants ≥18 years of age who are/were immunocompromised at the time of initial RSVpreF vaccination, per study protocol, and will be grouped based on prior RSV vaccination history:
  • Group 1 will include participants naïve to any RSV vaccine.
  • Group 2 will include participants who received a single prior dose of RSVpreF (Abrysvo) approximately 1 year (9 to 15 months) prior to enrollment.
  • Group 3 will include participants who received a single prior dose of RSVpreF (Abrysvo) approximately 2 years (21 to 27 months) prior to enrollment.
  • Group 4 will include participants who previously received 2 doses of RSVpreF in Study C3671023 Substudy B approximately 3 years (36 to 42 months) prior to enrollment.
  • Participants should have a life expectancy ≥12 months (365 days) in the opinion of the investigator at enrollment.

Key Exclusion Criteria:

  • Prior history of any subtype of Guillain-Barré Syndrome (GBS) of any etiology.
  • History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any components of the study intervention(s).
  • Participants with a history of transplant rejection, or PTLD, or participants who have had treatment for these conditions, within 90 days prior to study enrollment or suspected chronic humoral or cellular rejection.
  • Receipt of B-cell depleting therapies within 180 days prior to initial study vaccination.

Refer to the study contact for further eligibility details.

Study Design

Enrollment

440 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

experimental: Group 1

RSVpreF Vaccine

experimental: Group 2

RSVpreF Vaccine

experimental: Group 3

RSVpreF Vaccine

experimental: Group 4

RSVpreF Vaccine

Interventions

RSVpreF Vaccine

RSVpreF Vaccine

Primary outcome measure

  • Percentage of participants reporting local reactions [ Time Frame: For up to 7 days after vaccination ]
  • Percentage of participants reporting systemic events [ Time Frame: For up to 7 days after vaccination ]
  • Percentage of participants reporting adverse events [ Time Frame: Through 1 month after vaccination ]
  • Percentage of participants reporting newly diagnosed chronic medical conditions [ Time Frame: Through 12 months after vaccination ]
  • Percentage of participants reporting serious adverse events [ Time Frame: Through 12 months after vaccination ]
  • Neutralizing Titers (NTs) for RSV A and RSV B expressed as Geometric Mean Titer (GMT) [ Time Frame: Before vaccination, 1 month, 6 months and 12 months after vaccination ]
  • NTs for RSV A and RSV B expressed as Geometric Mean Fold Rise (GMFR) [ Time Frame: Before vaccination, 1 month, 6 months and 12 months after vaccination ]

Central Contacts and Locations

Central contacts

Pfizer CT.gov Call Center

1-800-718-1021ClinicalTrials.gov_Inquiries@pfizer.com

Locations

Kaiser Foundation Hospital LAMC

Recruiting

Los Angeles, California, United States, 90027

Kaiser Permanente Los Angeles Medical center

Recruiting

Los Angeles, California, United States, 90027

Kaiser Permanente

Recruiting

Los Angeles, California, United States, 90027

More Information

Sponsor

Pfizer

Last update posted

Sep 8, 2026

Last verified

Sep, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Pfizer on 2026-09-08.