Study of VYD2311 for the Prevention of COVID-19 (DECLARATION)

May 12, 2026 updated by: Invivyd, Inc.

A Phase 3, Randomized, Triple-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of VYD2311 for the Prevention of COVID-19 in Adults and Adolescents

The main purpose of this study is to test an investigational drug known as VYD2311, which is being developed to lower the risk of getting COVID-19. VYD2311 is a monoclonal antibody that attaches to the virus that causes COVID-19 and helps block it from entering your cells. It is being tested in adults and adolescents at least 12 years old. Participants in this study will be given a "study drug" that will be either VYD2311 or placebo.

The study drug will be given as a shot into the muscle in the participant's upper thigh or upper arm once a month with a total of 3 shots during the study.

This study will help researchers see how well VYD2311 works to prevent COVID-19 during the 90 days after the first shot. The study will also look at the safety and tolerability of VYD2311, how the study drug is processed by the body (pharmacokinetics), how the immune system reacts to the study drug (immunogenicity), and how well VYD2311 can block the virus from infecting cells (neutralization). To do these tests, your blood will be drawn at certain times during the study.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

1770

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • California
      • Long Beach, California, United States, 90806
      • San Diego, California, United States, 92103
    • Florida
      • Orlando, Florida, United States, 32819
    • Georgia
      • Hinesville, Georgia, United States, 31313
        • Recruiting
        • Invivyd Investigative Site
        • Principal Investigator:
          • Declaration
        • Contact:
    • Illinois
      • Melrose Park, Illinois, United States, 60160
    • Kansas
      • Lenexa, Kansas, United States, 66219
    • Maryland
      • Silver Spring, Maryland, United States, 20904
    • Massachusetts
      • Burlington, Massachusetts, United States, 01803
    • Michigan
      • Southfield, Michigan, United States, 48034
    • Minnesota
      • Maplewood, Minnesota, United States, 55109
    • Missouri
      • Independence, Missouri, United States, 64055
    • New Jersey
      • Jersey City, New Jersey, United States, 07306
    • New York
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19107
    • South Carolina
      • Myrtle Beach, South Carolina, United States, 29572
    • Tennessee
      • Goodlettsville, Tennessee, United States, 37072
    • Texas
      • Houston, Texas, United States, 77065
      • Houston-2, Texas, United States, 77065
      • Irving, Texas, United States, 75061
      • Sugar Land, Texas, United States, 46254

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

Participants are eligible to be included in the study only if all the following criteria apply:

  1. Is an adult aged ≥18 years or an adolescent aged 12 to <18 years weighing at least 40 kg at the time of Screening. Note: Adolescent enrollment is allowed only if permitted by the local health authorities and local ethics committees.
  2. Has uninterrupted access to a device (eg, mobile phone, tablet) enabled to receive study reminders (eg, SMS text messages). The parent/guardian of adolescent participants will receive the study reminders.
  3. Provides written documentation of informed consent by signing a current IEC/IRB-approved ICF at the time of Screening. In the case of adolescents, parental informed consent and adolescent assent must also be obtained.
  4. Is able to understand and comply with study requirements/procedures (if applicable, with assistance by a caregiver, surrogate, or LAR) based on the assessment of the Investigator.

  5. For participants assigned female sex at birth:

    1. Is not of childbearing potential, OR
    2. Is of childbearing potential and practicing adequate contraception for at least 7 days before dosing on Day 1, agrees to practice adequate contraception through 6 months after any dosing, and has a negative pregnancy test result on Day 1.

Note: Pregnant participants will be eligible for enrollment after iDMC review of safety data only upon Sponsor communication to sites and only in regions permitted by local health authorities and local ethics committees. If pregnant participants are eligible for enrollment, this criterion is no longer applicable.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

  1. Prior receipt of VYD2311 or pemivibart (VYD222) within 12 months before Day 1 or plans to receive pemivibart within 90 days after Day 1.
  2. Prior receipt of convalescent plasma or a mAb to SARS-CoV-2 active against currently circulating variants within 120 days before Day 1 or plans to receive convalescent plasma or an active SARS-CoV-2 mAb within 90 days after Day 1.
  3. Tests positive for current SARS-CoV-2 infection by local RAT or RT-PCR on Day 1.
  4. Prior known or suspected SARS-CoV-2 infection within 120 days before Day 1.
  5. Exposure to someone with known or suspected SARS-CoV-2 infection in the 5 days before Day 1.
  6. Is acutely ill, including symptoms suggestive of SARS-CoV-2 infection, in the opinion of the investigator or has a fever ≥38 o C (≥100.4 o F) within 3 days of Day 1.
  7. Received or plans to receive a non-COVID-19 vaccine within 7 days before or after each dose of study drug.

NOTE: Other protocol defined inclusion/exclusion criteria apply

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: VYD2311-SD (single dose)
VYD2311 administered via IM injection on Day 1, followed by placebo injection (0.9% sodium chloride [normal saline]) on Day 30 and Day 60
Drug: VYD2311-SD
VYD2311-SD (single-dose arm): Intramuscular injection dosing on Day 1 with VYD2311 and Intramuscular injection dosing Placebo (normal saline) on Day 30 and Day 60
Active Comparator: VYD2311-MD (multidose)
VYD2311 administered via IM injection on Day 1, Day 30, and Day 60
Drug: VYD2311-MD
VYD2311-MD (multi-dose): Intramuscular injection dosing on Day 1, Day 30, and Day 60 with VYD2311
Placebo Comparator: Placebo
Normal saline administered by IM injection on Day 1, Day 30, and Day 60
Drug: Placebo
Intramuscular injection dosing on Day 1, Day 30, and Day 60 with Placebo (Normal Saline)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
RT-PCR-confirmed symptomatic COVID-19 through Day 90
Time Frame: 90 days
90 days

Secondary Outcome Measures

Outcome Measure
Time Frame
Assessment of safety based on treatment-emergent adverse events, injection site reactions, and hypersensitivity reactions through Day 90
Time Frame: 90 days
90 days
Serum concentrations of VYD2311 through Day 90
Time Frame: 90 days
90 days
Incidence of ADAs against VYD2311 through Day 90
Time Frame: 90 days
90 days
Calculated sVNA titers (VYD2311 serum concentration/variant IC50) against relevant SARS-CoV-2 variants through Day 90
Time Frame: 90 days
90 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Invivyd, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 8, 2026

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

August 1, 2026

Study Registration Dates

First Submitted

December 18, 2025

First Submitted That Met QC Criteria

December 19, 2025

First Posted (Actual)

December 23, 2025

Study Record Updates

Last Update Posted (Actual)

May 15, 2026

Last Update Submitted That Met QC Criteria

May 12, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VYD2311-PREV-002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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