Phase 3 Study of Novavax Vaccine(s) as Booster Dose After mRNA Vaccines

NCT05875701 | Completed Phase 3 Results DMC FDA Drug

• 1 other identifier: 2019nCoV-312
• Study Type: interventional
• Target: 147
• Locations: 1 country
• Sites: 5

Brief Summary

This is an open-label Phase 3 study evaluating the immunogenicity and safety of Novavax vaccine(s) with Matrix-M™ adjuvant (ancestral strain NVX-CoV2373 and an alternative strain and/or multivalent Novavax vaccine) as booster doses following a series of primary and booster doses of authorized/approved mRNA vaccines followed by a single booster dose of NVX-CoV2373 in the Novavax 2019nCoV-307 study (NCT05463068).

Conditions

COVID-19

Outcome Measures

Primary Outcomes (1)

• Neutralizing Antibody (Nab) for SARS-CoV-2 Wildtype Virus (Wuhan) Responses Expressed as Geometric Mean Titers (GMT)

  Neutralizing Antibody responses to ancestral strain Novavax vaccine (NVX-CoV2373) for the participants in the ancestral strain NVX-2373 group and NVX-CoV2540 group at Day 29

  Day 28

Secondary Outcomes (10)

• Neutralizing Antibody (Nab) for SARS-CoV-2 Wildtype Virus (Wuhan) Responses Expressed as Seroconversion Rate (SCR)

  Day 28

• Serum Immunoglobulin G (IgG) ELISA Units to SARS-CoV-2 Spike Protein (Wuhan) Expressed as Geometric Mean ELISA Unit (GMEU)

  Day 28

• Serum Immunoglobulin G (IgG) ELISA Units to SARS-CoV-2 Spike Protein (Wuhan) Expressed as SCR

  Day 28

• Neutralizing Antibody Responses (Post-Booster) Expressed as GMT

  Day 0 and Day 28 of Study 307 and Study 312 (approximately 1 year from Day 0 of Study 307 and Day 0 of Study 312)

• Serum IgG Antibody Levels (Post-Booster) Expressed as GMEU

  Day 0 and Day 28 of Study 307 and Study 312 (approximately 1 year from Day 0 of Study 307 and Day 0 of Study 312)

Study Arms (2)

NVX CoV2373 (Ancestral strain)

EXPERIMENTAL

1dose of NVX-COV2373 on Day 1

Biological: NVX-CoV2373

Updated COVID-19 Vaccine

EXPERIMENTAL

1dose of updated COVID-19 vaccine on Day 1

Biological: SARS-CoV-2 rS antigen/Matrix-M Adjuvant

Interventions

NVX-CoV2373 BIOLOGICAL

1 intramuscular (IM) injection of 5 µg SARS-CoV-2 rS + 50 µg Matrix-M1 adjuvant (0.5 mL) given on Day 1

Also known as: SARS-CoV-2 rS/Matrix-M Adjuvant

NVX CoV2373 (Ancestral strain)

SARS-CoV-2 rS antigen/Matrix-M Adjuvant BIOLOGICAL

1 intramuscular (IM) injection of 5 µg SARS-CoV-2 rS antigen+ 50 µg Matrix-M1 adjuvant (0.5 mL) given on Day 1

Also known as: Updated Novavax COVID-19 vaccine

Updated COVID-19 Vaccine

Eligibility Criteria

• Age: 18 Years - 49 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• To be included in this study, each individual must satisfy all the following criteria:
• Adults 18 to 49 years (inclusive) of age at the time of vaccination in Study 307 who received two or three doses of mRNA prior to enrollment in Study 307, then one dose of ancestral strain NVX-CoV2373 in Study 307.
• Willing and able to give informed consent prior to study enrollment and to comply with study procedures.
• 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 \[defined as amenorrhea at least 12 consecutive months\]) must agree to be heterosexually inactive from at least 28 days prior to enrollment and through the end of study (EOS) visit OR agree to consistently use a medically acceptable method of contraception from at least 28 days prior to enrollment and through the EOS visit.
• 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 the study vaccination.
• Agree to not participate in any 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.
• Documented receipt of COVID-19 vaccines. The most recent dose of NVX-CoV2373 must have been administered at least 180 days prior to vaccination in this study.

You may not qualify if:

• Participants meeting any of the following criteria will be excluded from the study.
• Received any additional COVID-19 vaccine booster after the Day 1 dose of NVX-CoV2373 administered during participation in Study 307.
• History of laboratory-confirmed (by polymerase chain reaction \[PCR\] or rapid antigen test) COVID-19 infection ≤ 4 months prior to Day 1.
• Current participation in research involving receipt of an investigational product (drug/biologic/device).
• Any known allergies or history of anaphylaxis to the active substance or any of the other ingredients contained in the investigational product.
• Any autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) or therapy that causes clinically significant immunosuppression.
• Received any vaccine ≤ 90 days prior to study vaccination, except for influenza vaccine which may be received \> 4 days prior to study vaccine, or rabies vaccine, which may be received at any time if medically indicated.
• Received immunoglobulin, blood-derived products, or immunosuppressant drugs within 90 days prior to study vaccination, except for rabies immunoglobulin which may be given if medically indicated.
• Active cancer (malignancy) on chemotherapy that is judged to cause significant immunocompromise within 1 year prior to first study vaccination (with the exception of malignancy cured via excision, at the discretion of the investigator).
• Participants who are breastfeeding, pregnant, or who plan to become pregnant prior to the EOS visit.
• Suspected or known history of alcohol abuse or drug addiction within 3 months prior to the study vaccine dose 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 trial vaccine or interpretation of study results (including 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).
• Participants with a history of myocarditis or pericarditis.

Sponsors & Collaborators

• Novavax: lead

Study Sites (5)

Benchmark Research

Austin, Texas, 78705, United States

Location

Tekton Research

Austin, Texas, 78747, United States

Location

Benchmark Research

Fort Worth, Texas, 76135, United States

Location

Research Your Health

Plano, Texas, 75093, United States

Location

Tekton Research

San Antonio, Texas, 78229, United States

Location

MeSH Terms

Conditions

COVID-19

Interventions

NVX-CoV2373 adjuvated lipid nanoparticle

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Results Point of Contact

• Title: Novavax Customer Service Center
• Organization: Novavax Inc.

Clinicaltrials@novavax.com

1-844-Novavax (668-2829)

Study Officials

• Clinical Development

  Novavax, Inc.

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 16, 2023
• First Posted: May 25, 2023
• Study Start: March 28, 2023
• Primary Completion: November 11, 2023
• Study Completion: November 11, 2023
• Last Updated: June 26, 2025
• Results First Posted: June 26, 2025

Record last verified: 2025-06

Locations

US (5)