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COVID-19Phase 2/3COVID-19NCT05975060

A Study to Evaluate the Safety and Immunogenicity of an (Omicron Subvariant) COVID-19 Vaccine Booster Dose in Previously Vaccinated Participants and Unvaccinated Participants.

A Phase 2/3 study testing XBB.1.5 Vaccine (Booster) and XBB.1.5 Vaccine (single dose) in people with COVID-19, run by Novavax at 30 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This is a Phase 2/3 open-label study to evaluate the safety and immunogenicity of a booster dose of the XBB.1.5 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant (r) spike (S) protein nanoparticle vaccine (SARS-CoV-2 rS) adjuvanted with Matrix-M™ in previously mRNA COVID-19 vaccinated adult… Read more about this study

Who is it for?
Ages 18 to 54 years
Conditions the study is for
COVID-19
What is being tested?
XBB.1.5 Vaccine (Booster) and XBB.1.5 Vaccine (single dose)
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
660 participants
Where
30 sitesUnited States
Study dates
7 Sep 2023to 20 May 2024
Phase
Phase 2/3
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 54 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Adults ≥ 18 years of age at time of study vaccination.
  • Part 1: Previously vaccinated with ≥ 3 doses of the Moderna and/or Pfizer /BioNTech prototype monovalent and/or BA.4/5 containing bivalent COVID-19 vaccines with the last dose administered ≥ 90 days prior to study vaccination.
  • Part 2: Clinical history of COVID-19-like disease during the previous year.
  • Willing and able to give informed consent prior to study enrollment and to comply with study procedures.
  • Female participants of childbearing potential (defined as any participant who has experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral tubal ligation, or bilateral oophorectomy] or postmenopausal [defined as amenorrhea ≥ 12 consecutive months]) must agree to be heterosexually in-active from at least 28 days prior to enrollment and through the end of the study OR agree to consistently use a medically acceptable method of contraception listed below from ≥ 28 days prior to enrollment and through the end of the study.
  • Condoms (male or female) with spermicide (if acceptable in country)
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  • Diaphragm with spermicide
  • Cervical cap with spermicide
  • Intrauterine device
  • Oral or patch contraceptives
  • Norplant®, Depo-Provera®, or other in country regulatory approved contraceptive method that is designed to protect against pregnancy.
  • Abstinence, as a form of contraception, is acceptable if in line with the participant's lifestyle NOTE: Periodic abstinence (eg, calendar, ovulation, sympto-thermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception.
  • Is medically stable, as determined by the investigator (based on review of health status, vital signs [to include body temperature], medical history, and physical examination [to include body weight]). Vital signs must be within medically acceptable ranges prior to study vaccination.
  • Agrees to not participate in any research involving receipt of investigational products (drug/biologic/device) including other SARS-CoV-2 prevention or treatment trials for the duration of the study.
  • NOTE: For participants who become hospitalized with COVID-19, participation in investigational treatment studies is permitted.

Who cannot join

  • Received COVID-19 vaccines other than Moderna and/or Pfizer-BioNTech in the past, inclusive of clinical trial COVID-19 vaccines.
  • Participation in research involving receipt of investigational products (drug/biologic/device) within 90 days prior to study vaccination (Day 0).
  • Received influenza vaccination within 14 days prior to study vaccination, or any other vaccine within 30 days prior to study vaccination.
  • Any known allergies to products contained in the investigational product.
  • Any history of anaphylaxis to any prior vaccine.
  • Autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) requiring ongoing immunomodulatory therapy.
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  • NOTE: Stable endocrine disorders (eg, thyroiditis, pancreatitis), including stable diabetes mellitus with no history of diabetic ketoacidosis are NOT excluded.
  • Chronic administration (defined as > 14 continuous days) of immunosuppressant, systemic glucocorti-coids, or other immune-modifying drugs within 90 days prior to study vaccination (Day 0).
  • NOTE: An immunosuppressant dose of glucocorticoid is defined as a systemic dose ≥ 10 mg of prednisone per day or equivalent. The use of topical or intranasal glucocorticoids is permitted. Topical tacrolimus and ocular cyclosporin are permitted. Use of inhaled glucocorticoids is prohibited.
  • Received any prohibited medication (see Section 7.4.1), immunoglobulin, blood-derived products, or immunosuppressant drugs within 90 days prior to study vaccination (Day 0).
  • Active cancer (malignancy) on chemotherapy within 3 years prior to first study vaccination (with the exception of adequately treated non-melanomatous skin carcinoma or lentigo malign and uterine cervical carcinoma in situ without evidence of disease, at the discretion of the investigator).
  • Participants who are breastfeeding, pregnant, or who plan to become pregnant prior to the end of study.
  • Suspected or known history of alcohol abuse or drug addiction within 2 years prior to study vaccination that, in the opinion of the investigator, might interfere with protocol compliance.
  • Any other condition that, in the opinion of the investigator, would pose a health risk to the participant if enrolled or could interfere with evaluation of the study vaccine or interpretation of study results (includ-ing neurologic or psychiatric conditions likely to impair the quality of safety reporting).
  • Study team member or immediate family member of any study team member (inclusive of Sponsor, clinical research organization [CRO], and study site personnel involved in the conduct or planning of the study).
  • Known history of myocarditis or pericarditis.
  • Respiratory symptoms in the past 3 days (ie, cough, sore throat, difficulty breathing).
  • Temperature of > 38°C within 24 hours of planned study vaccination (site measured or participant meas-ured).
  • Blood pressure of ≥ 160/100 mmHg.

Trial locations and contacts

30 sites in 1 country.

30 sites in 1 country

United States30 sites

  • AXCES Research

    Albuquerque, New Mexico, 87109

  • Benchmark Research

    Austin, Texas, 78705

  • Tekton Research

    Austin, Texas, 78745

  • University of Maryland

    Baltimore, Maryland, 21201

  • Tekton Research

    Beaumont, Texas, 77706

  • Pan American clinical Research,LLC

    Brownsville, Texas, 78520

  • Lynn Institute of the Rockies

    Colorado Springs, Colorado, 80918

  • AMR LLC-Miami

    Coral Gables, Florida, 33134

  • AMR

    Fort Myers, Florida, 33912

  • Benchmark Research

    Fort Worth, Texas, 76135

  • Health Awareness,LLC

    Jupiter, Florida, 33458

  • AMR

    Kansas City, Missouri, 64114

  • AMR

    Knoxville, Tennessee, 37909

  • AMR

    Las Vegas, Nevada, 89119

  • Tekton Research

    Lawrenceville, Georgia, 30046

  • AMR Layton Research Centre

    Layton, Utah, 84041

  • AMR

    Mobile, Alabama, 36608

  • AMR New Orleans

    New Orleans, Louisiana, 70119

  • Health Research of Hampton Roads

    Newport News, Virginia, 23606

  • Alliance for Multispecialty RSCH

    Newton, Kansas, 67114

  • Velocity Clinical Research

    Norfolk, Nebraska, 68701

  • DM Clinical Research

    Philadelphia, Pennsylvania, 19147

  • Research For Your Health

    Plano, Texas, 75093

  • Rochester Clinical Research

    Rochester, New York, 14609

  • Benchmark Research

    Sacramento, California, 95864

  • Tekton Research

    San Antonio, Texas, 78229

  • University of Washington

    Seattle, Washington, 98104

  • Sundance Clinical Research

    St Louis, Missouri, 63141

  • Tekton Research

    Wichita, Kansas, 67218

  • Tekton Research

    Yukon, Oklahoma, 73099

Other trials in United States

About this study

Official title: A Phase 2/3 Open-Label Study to Evaluate the Safety and Immunogenicity of an XBB.1.5 (Omicron Subvariant) SARS CoV-2 rS Vaccine Booster Dose in Previously mRNA COVID 19 Vaccinated and Baseline SARS CoV 2 Seropositive COVID-19 Vaccine Naïve Participants

This is a Phase 2/3 open-label study to evaluate the safety and immunogenicity of a booster dose of the XBB.1.5 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant (r) spike (S) protein nanoparticle vaccine (SARS-CoV-2 rS) adjuvanted with Matrix-M™ in previously mRNA COVID-19 vaccinated adult participants ≥18 years of age and baseline SARS CoV-2 seropositive COVID-19 vaccine naïve participants ≥18 years of age.

Read the detailed description

Novavax, Inc. developed a recombinant prototype COVID-19 vaccine constructed from the full-length ancestral (Wuhan) SARS CoV-2 S glycoprotein (GP) adjuvanted with the saponin-based Matrix-M adjuvant (NVX-CoV2373). Subsequently, the SARS CoV 2 Omicron variant and subvariants emerged with enhanced transmissibility and the most significant number of mutations in any strain to date. Current evidence demonstrates that variant strain mutations such as those in the Omicron XBB.1.5 sublineage confer the ability to evade both natural and vaccine-induced neutralizing antibodies.

Part 1 of the study aims to investigate the safety and immunogenicity of the Novavax XBB.1.5 SARS-CoV-2 rS vaccine (NVX-CoV2601) adjuvanted with Matrix-M in previously COVID-19 mRNA vaccinated participants to determine if it induces superior antibody responses compared to a historical control of the prototype vaccine (original Wuhan strain), NVX-CoV2373.

Part 2 of the study aims to investigate the safety and immunogenicity of 1 dose of NVX CoV2601 in baseline SARS-CoV-2 seropositive COVID-19 vaccine naïve participants to determine if it induces non-inferior antibody responses compared to 1 booster dose of NVX-CoV2601 in previously COVID-19 mRNA vaccinated individuals participating in Part 1.

Part 1:

Approximately 330 previously mRNA COVID-19 vaccinated participants will receive a booster dose of XBB.1.5 Omicron subvariant vaccine (NVX-CoV2601) on Day 0. Immunogenicity and 28-day safety data will be used for an interim analysis, while participants remain on the study for immunogenicity and safety data collection up to Day 180 post-vaccination.

Part 2:

After completion of Part 1, approximately 330 unvaccinated participants with a clinical history of COVID-19-like disease during the previous year will receive a booster dose of NVX-CoV2601 on Day 0. Immunogenicity and 28-day safety data will be used for an interim analysis, while participants remain on the study for immunogenicity and safety data collection up to Day 180 post vaccination.

Conditions
COVID-19
Being tested
XBB.1.5 Vaccine (Booster), XBB.1.5 Vaccine (single dose)
Keywords
COVID-19, XBB.1.5
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • XBB.1.5 Vaccine (Booster)Biological

    Also called Omicron sub variant XBB.1.5 vaccine( booster) SARS-CoV-2 rS /Matrix-M Adjuvant

    Omicron sub variant XBB.1.5 SARS-CoV-2 rS /Matrix-M Adjuvant the monovalent [5 μg/50 μg] NVX-CoV2601) XBB.1.5 Vaccine (Booster)

  • XBB.1.5 Vaccine (single dose)Biological

    Also called Omicron sub variant XBB.1.5 vaccine(single dose) SARS-CoV-2 rS /Matrix-M Adjuvant

    Omicron sub variant XBB.1.5 SARS-CoV-2 rS /Matrix-M Adjuvant the monovalent [5 μg/50 μg] NVX-CoV2601) XBB.1.5 Vaccine ( single dose)

Study groups in NCT05975060
Study groupRoleWhat they receive
Group-A XBB.1.5 Vaccine (Booster)ExperimentalThe Monovalent [5 μg/50 μg] NVX-CoV2601 XBB.1.5 Vaccine (Booster)
Receives: Biological: XBB.1.5 Vaccine (Booster)
Group-B The monovalent XBB.1.5 Vaccine (Single Dose).Active comparatorGroup-B The monovalent [5 μg/50 μg] NVX-CoV2601 XBB.1.5 Vaccine (Single Dose).
Receives: Biological: XBB.1.5 Vaccine (single dose)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Part 1: Pseudovirus neutralization (inhibitory dilution at a concentration of 50%; ID 50 ) to the NVX-CoV2601 vaccine

    Pseudovirus neutralization (inhibitory dilution at a concentration of 50%; ID 50 ) to the NVX-CoV2601 vaccine assessed at Day 28 following study vaccination.

    Measured: Day 28

  2. Part 1: Seroresponse Rates (SRRs) in ID 50 titers to the NVXCoV2601 vaccine

    SRRs (proportion of seroconverted participants) in ID 50 titers to the NVXCoV2601 vaccine assessed at Day 28 following the study vaccination.

    Measured: Day 28

  3. Part 2: SRRs in ID 50 titers to the XBB.1.5 Omicron subvariant

    SRRs (proportion of seroconverted participants) in ID 50 titers to the XBB.1.5 Omicron subvariant assessed at Day 28 following study vaccination.

    Measured: Day 28

  4. Part 2: ID 50 (Geometric Mean Titers) GMTs to the XBB.1.5 Omicron subvariant

    ID 50 GMTs to the XBB.1.5 Omicron subvariant assessed at Day 28 following study vaccination.

    Measured: Day 28

Secondary outcomes (12)

  1. Part 1: Pseudovirus neutralization (inhibitory dilution at a concentration of 50%; ID50) to the NVX-CoV2601 vaccine

    Pseudovirus neutralization (inhibitory dilution at a concentration of 50%; ID50) to the NVX-CoV2601 vaccine assessed at baseline and 28 days following study vaccination.

    Measured: Day 28

  2. Part 1: ID 50 GMTs to the XBB.1.5 Omicron subvariant

    ID 50 GMTs to the XBB.1.5 Omicron subvariant at relevant time points

    Measured: Day 0 to Day 180

  3. Part 1: ID 50 geometric mean fold rise (GMFR) to the XBB.1.5 Omicron subvariant at relevant time points (Days 28 and 180) from baseline (Day 0).

    ID 50 GMFR to the XBB.1.5 Omicron subvariant at relevant time points (Days 28 and 180) from baseline (Day 0).

    Measured: Day 0 to Day 180

  4. Part 1: SRRs in ID 50 titer concentrations to the XBB.1.5 Omicron subvariant at relevant time points.

    SRRs in ID 50 titer concentrations to the XBB.1.5 Omicron subvariant at relevant time points.

    Measured: Day 28 to Day 180

  5. Part 1: Anti-S immunoglobulin G (IgG) geometric mean concentrations (GMCs, EU/mL) to the NVX-CoV2601 vaccine at relevant time points

    Anti-S IgG geometric mean concentrations (GMCs, EU/mL) to the NVX-CoV2601 vaccine at relevant time points (Days 0, 28, and 180).

    Measured: Day 0 to Day 180

  6. Part 1: Incidence and severity of solicited local and systemic adverse events (AEs)

    Incidence, duration, and severity of solicited local and systemic adverse events (AEs) for 7 days following vaccination.

    Measured: Day 0 to Day 7

  7. Part 1: Incidence and severity of unsolicited AEs

    Incidence, severity, and relationship of unsolicited AEs through 28 days after vaccination.

    Measured: Day 28

  8. Part 1: Incidence and severity of MAAEs attributed to study vaccine, adverse events of special interest (AESIs), and serious adverse events (SAEs)

    Incidence and severity of Medically attended adverse event (MAAEs), adverse events of special interest (AESIs), and serious adverse events (SAEs) through day 180 or EOS.

    Measured: Day 0 to Day 180

  9. Part 2: Pseudovirus neutralization (ID 50 ) to the XBB.1.5 Omicron subvariant

    Pseudovirus neutralization (ID 50 ) to the XBB.1.5 Omicron subvariant assessed at baseline and at Day 28 following study vaccination.

    Measured: Day 0 to Day 28

  10. Part 2: Incidence and severity of solicited local and systemic adverse events (AEs)

    Incidence, duration, and severity of solicited local and systemic adverse events (AEs) for 7 days following vaccination.

    Measured: Day 0 to Day 7

  11. Part 2: Incidence, and severity of unsolicited AEs

    Incidence, severity, and relationship of unsolicited AEs through 28 days after vaccination.

    Measured: Day 28

  12. Part 2: Incidence and severity of MAAEs, AESIs, and SAEs

    Incidence and severity of MAAEs attributed to study vaccine, adverse events of special interest (AESIs) (predefined list including PIMMCs, myocarditis and/or pericarditis, and complications specific to COVID-19), and serious adverse events (SAEs) through day 180 or EOS.

    Measured: Day 0 to Day 180

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Aug 2023
  2. Study start7 Sep 2023
  3. Primary completion15 Nov 2023
  4. Study completion20 May 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2/3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Crossover
Masking
None (open label)
Enrolment
660 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05975060
Sponsor's protocol ID
2019nCoV-313
Acronym
COVID-19
Status last verified
May 2024
First submitted
28 Jul 2023
Last updated
30 May 2024
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No

Publications

  • Alves K, Kouassi A, Plested JS, Kalkeri R, Smith K, Kaba M, Nelson J, Zhu M, Cloney-Clark S, Cai Z, Mallory RM, Noriega F; 2019nCoV-313 Study Investigators. Immunogenicity and safety of a monovalent Omicron XBB.1.5 SARS-CoV-2 recombinant spike protein vaccine in previously unvaccinated, SARS-CoV-2 seropositive participants: Primary day-28 analysis of a phase 2/3 open-label study. Vaccine. 2025 May 10;55:127046. doi: 10.1016/j.vaccine.2025.127046. Epub 2025 Apr 2.

    PubMed 40184816

  • Alves K, Kotloff K, McClelland RS, Kouassi A, Plested JS, Kalkeri R, Zhu M, Cloney-Clark S, Cai Z, Smith K, Kaba M, Nelson J, Hammershaimb EA, Mallory RM, Noriega F; 2019nCoV-313 Study Investigators. Immunogenicity and safety of a monovalent omicron XBB.1.5 SARS-CoV-2 recombinant spike protein vaccine as a heterologous booster dose in US adults: interim analysis of a single-arm phase 2/3 study. Lancet Infect Dis. 2025 May;25(5):585-594. doi: 10.1016/S1473-3099(24)00670-4. Epub 2025 Jan 14.

    PubMed 39824198

Questions about this trial

What is this clinical trial studying?

A Phase 2/3 study testing XBB.1.5 Vaccine (Booster) and XBB.1.5 Vaccine (single dose) in people with COVID-19, run by Novavax at 30 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 15 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 30 May 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 30 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part 1: Pseudovirus neutralization (inhibitory dilution at a concentration of 50%; ID 50 ) to the NVX-CoV2601 vaccine (time frame: Day 28). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05975060, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 May 2024.

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