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NCT06866405 · ClinicalTrials.gov registry record · Phase 3

A Phase 3 Study of Revaccination in Subsequent Pregnancies With Bivalent RSV Vaccine and Duration of Protection of a Single Dose

A Phase 3 study of RSV Infection, sponsored by Pfizer.

Recruiting
Registry status
Phase 3
Development phase
550
Enrollment target
20
Study locations

NCT06866405: Recruiting Phase 3 study of RSV Infection, sponsored by Pfizer.

NCT06866405 is a Phase 3 study of RSV Infection that is actively recruiting participants, run by Pfizer. The registered enrollment target is 550 participants, below the 678-participant average among 8 other RSV Infection trials with a reported enrollment target (19% lower). The trial reports 20 study locations across 3 states. According to ClinicalTrials.gov, the official US trial registry.

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The verdict

NCT06866405, a Phase 3 study of RSV Infection, is actively recruiting participants, sponsored by Pfizer.

RECRUITING
Registry status
Phase 3
Development phase
550 participants
Enrollment target
20
Study locations

Study Summary

This study aims to check how safe and well-tolerated a second dose of RSVpreF is when given during later pregnancies, and to see how long the immunity lasts from a single dose given during a previous pregnancy by examining the blood of nonpregnant participants who had the vaccine before.

Primary Outcome

Pain at the injection site, redness, and swelling

Conditions Studied

Interventions

  • BIOLOGICAL Placebo
  • BIOLOGICAL RSVpreF

Study Locations (20)

California

  • Ronald Reagan UCLA Medical Center - Los Angeles
  • Ronald Reagan UCLA Medical Center (inpatient hospital) - Los Angeles
  • Ronald Reagan UCLA Medical Center - Los Angeles
  • UCLA (outpatient clinic) - Los Angeles
  • UCLA Clinical and Translational Research Center (research clinic) - Los Angeles
  • UCLA - Los Angeles
  • Lucile Packard Children's Hospital-Labor and Delivery Unit - Palo Alto
  • Stanford Obstetrics Clinic - Palo Alto
  • Stanford University Medical Center - Palo Alto
  • Stanford University - Palo Alto

Alabama

  • Center for Research in Women's Health - Birmingham
  • Children's of Alabama - Birmingham
  • University of Alabama at Birmingham - School of Medicine - Birmingham
  • University of Alabama at Birmingham Women & Infants Center - Birmingham
  • USA Health Children's and Women's Hospital - Mobile
  • USA Health Strada Patient Care Center - Mobile

Colorado

  • Anschutz Health Sciences Building (AHSB) - Aurora
  • Children's Hospital Colorado - Aurora
  • CU Research Pharmacy - Aurora
  • University of Colorado AO1 UCH - Aurora

Trial Details

FieldValue
Enrollment Target 550 participants
Start Date 2025-04-16
Est. Completion 2028-02-24
Phase Phase 3
Pfizer

1,845 total trials

What NCT06866405 shows while recruiting

NCT06866405 is an interventional study that assigns participants to a tested intervention. The registered 550 participants enrollment target is mid-sized for trials with a published cap, below the 678-participant average among 8 other RSV Infection trials with a reported enrollment target (19% lower).

The record links to 1 condition, with RSV Infection appearing as the primary indexed condition, and to 2 interventions - of which Placebo is the first listed.

NCT06866405 names 20 study sites across 3 states, led by California, Alabama, Colorado.

Frequently Asked Questions

What is clinical trial NCT06866405 about?

NCT06866405 is a clinical study titled "A Phase 3 Study of Revaccination in Subsequent Pregnancies With Bivalent RSV Vaccine and Duration of Protection of a Single Dose". This study aims to check how safe and well-tolerated a second dose of RSVpreF is when given during later pregnancies, and to see how long the immunity lasts from a single dose given during a previous pregnancy by examining the blood of nonpregnant participants who had the vaccine before.

What is the current status of trial NCT06866405?

This trial is currently recruiting. It is a Phase 3 study. The enrollment target is 550 participants. The study started on 2025-04-16. Estimated completion is 2028-02-24.

What conditions does trial NCT06866405 study?

This clinical trial studies the following conditions: RSV Infection.

What interventions are being tested in trial NCT06866405?

The interventions under investigation include: Placebo (BIOLOGICAL), RSVpreF (BIOLOGICAL).

Who is sponsoring clinical trial NCT06866405?

This trial is sponsored by Pfizer, which has 1,845 total clinical trials registered on ClinicalTrials.gov.

Where is trial NCT06866405 being conducted?

This trial has 20 study locations across Alabama, California, Colorado. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.

Similar trials for RSV Infection

Matched on the same primary condition, ranked to surface studies in the same phase first, then by recruiting status, no relevance scoring or editorial curation.

Where NCT06866405's enrollment target sits among peer trials

550 3rd of 8 higher than 6 of 8 other RSV Infection trials

participants (enrollment target), bucketed by value

Each bar is a band; taller bars hold more other RSV Infection trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source ClinicalTrials.gov registry export · 2026-08-08

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Source: ClinicalTrials.gov NCT06866405, the US trial registry maintained by the National Library of Medicine. NCT06866405 (mid enrollment · wide site footprint · recruiting) retrieved and formatted by PlainTrial, see methodology.