> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/phase-2-3-heterologous-boosting-study-with-different-dose-11366f7d-0e56-4e5c-ad7c-d51c224636f4 > Record changed: 2026-10-13 # Phase 2/3 Heterologous Boosting Study With Different Dose Levels of Monovalent SARS-CoV-2 rS Vaccines NCT05925127 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Phase Phase 2/Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Participants 994 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Lead sponsor Novavax Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Start date 2023-10-16 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) Number of sites 50 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Title and summary **Summary** This is a Phase 2/3, randomized, double-blind study to evaluate the safety and immunogenicity of different booster dose levels of the monovalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant (r) spike (S) protein nanoparticle (SARS-CoV-2 rS) vaccines with Matrix-M™ adjuvant (NVX-CoV2373 \\\[prototype Wuhan vaccine with Matrix-M adjuvant\\\] or NVX-CoV2601 \\\[Omicron XBB.1.5 subvariant vaccine with Matrix-M adjuvant\\\]). Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Acronym** COVID-19 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Short title** Phase 2/3 Heterologous Boosting Study With Different Dose Levels of Monovalent SARS-CoV-2 rS Vaccines Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Official title** A Phase 2/3, Randomized, Double-Blind Study to Evaluate the Safety and Immunogenicity of Different Booster Dose Levels of Monovalent SARS-CoV-2 rS Vaccines in Adults ≥ 50 Years Previously Vaccinated With COVID-19 mRNA Vaccines Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Status and phase **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Phase** Phase 2/Phase 3 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Dates **Completion date** 2024-05-21 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **First posted** 2023-06-29 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Registry last updated** 2024-12-13 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Primary completion date** 2024-05-21 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Start date** 2023-10-16 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Size and sites **Actual participants** 994 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Participants** 994 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Protocol amendments** 7 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Randomisation ratio** 1:2:2:2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Number of sites** 50 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Lead sponsor** Novavax Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Identifiers **Registry ID** NCT05925127 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **ClinicalTrials.gov ID** NCT05925127 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Study design **Allocation** Randomised **Model** Crossover **Purpose** Prevention **Masking** Double masking **Masked roles** Participants, Investigators Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Outcomes ### Primary outcomes 1. Immunogenicity index-Neutralizing antibody expressed as geometric mean titer ratio\[GMTR \]against the Omicron subvariant XBB.1.5 Timeframe: Day 28 Neutralizing antibody To determine if the combination of antigen and adjuvant levels of NVX-CoV2601 GMTR against the Omicron subvariant XBB.1.5 superior(LB of the 95% CI for GMTR \\> 1.0) to that elicited by NVX-CoV2373 2. Immunogenicity index-Neutralizing antibody expressed as seroresponse rates (SRRs)against the Omicron subvariant XBB.1.5 Timeframe: Day 28 Neutralizing antibody SRR against the Omicron XBB.1.5 subvariant elicited by NVXCoV2601 is non-inferior (NI)to the SRR elicited by NVX-CoV2373in participants ≥ 50 years of age previously vaccinated with ≥ 3 doses of a COVID-19 prototype or bivalent licensed mRNA vaccine. ### Secondary outcomes 1. Neutralizing antibody expressed as geometric mean titer ratio\[GMTR \]against the Omicron subvariant XBB.1.5 Timeframe: Day 28 Neutralizing antibody (GMTR) at relevant time points Days 28 to 180 from baseline (Day 0) and analyzed by dose (5, 10, and 25 µg) 2. Immunogenicity index- IgG antibody Anti-S expressed as geometric mean Elisa units GMEUs (EU/mL) Timeframe: Day 0 to 180 Immunoglobulin G (IgG) antibody Anti-S expressed as geometric mean Elisa units GMEUs (EU/mL) at relevant time points (Days 0 to 180) and analyzed by dose (5, 10, and 25 µg) 3. Immunogenicity index- Neutralizing antibody titers of post-booster by baseline anti-SARS-CoV-2 NP Timeframe: Day-28 Neutralizing antibody titers of post-booster by baseline anti-SARS-CoV-2 NP status day-28 4. Immunogenicity index- Serum IgG levels to SARS-CoV-2 S protein at Day 28 of post-booster Timeframe: Day-28 Serum IgG levels to SARS-CoV-2 S protein at Day 28 post-booster by baseline anti-SARS-CoV-2 NP status. 5. Safety Index-Incidence, duration, and severity of solicited local and systemic AEs expressed as GMT Timeframe: 7 days Incidence, duration, and severity of solicited local and systemic AEs for 7 days following vaccination. 6. Safety Index -Incidence and relationship of Medically Attended Adverse Event(s) (MAAEs), Adverse event(s) of Special Interest (AESIs), and Serious Adverse Event(s) (SAEs) Timeframe: Day 0 to 180 Incidence and relationship of Medically Attended Adverse Event(s) (MAAEs), Adverse event(s) of Special Interest (AESIs), and Serious Adverse Event(s) (SAEs) \\\[ Time Frame: Day 0 to Day 180 \\\] Incidence and relationship of MAAEs, AESIs (predefined list), and SAEs throughout the study 7. Safety Index -Incidence, Severity, and relationship of unsolicitated Adverse Event(s) Through 28 days after vaccination by vaccine group p(vaccine groups A to G). Timeframe: Day 0 to 180 Incidence, Severity, and relationship of unsolicitated Adverse Event(s) Through 28 days after vaccination by vaccine group p(vaccine groups A to G).s the overall safety of single-dose regimens containing NVX-CoV2601, NVX-CoV2373, or mRNA vaccine by vaccine group in participants ≥ 50 years of age previously vaccinated with ≥ 3 doses of a COVID-19 prototype or bivalentlicensed mRNA vaccine. 8. Human angiotensin-converting enzyme 2 (hACE2) receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 viruses expressed as GMTs Timeframe: Day 0 to 180 hACE2 receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 viruses at relevant time points (Days 0, 28, and 180) and analyzed by dose (5, 10, and 25 µg) 9. hACE2 receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 viruses expressed as GMFR Timeframe: Day 0 to 180 hACE2 receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 viruses at relevant time points (Days 0, 28, and 180) and analyzed by dose (5, 10, and 25 µg). 10. hACE2 receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 S proteins expressed as SRR Timeframe: Day 0 to 180 hACE2 receptor binding inhibition assay to the ancestral (Wuhan), Omicron BA.1, and Omicron BA.5 S proteins at relevant time points (Days 0, 28, and 180)and analyzed by previous vaccine combination received. Derived/calculated endpoints based on these data will include SRRs. Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 50 Years **Maximum age** 99 Years **Healthy volunteers** Yes ### Inclusion criteria 1. Adults ≥ 50 years of age at screening. 2. Willing and able to give informed consent prior to study enrollment and to comply with study procedures. 3. 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 inactive 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. 4. Is medically stable, as determined by the investigator (based on review of health status, vital signs \[to include body temperature\], medical history, and targeted physical examination \[to include body weight\]). Vital signs must be within medically acceptable ranges prior to the initial study vaccination. 5. Agrees to not participate in any other SARS-CoV-2 prevention or treatment trials for the duration of the study. 6. Have previously received ≥ 3 doses of a COVID-19 prototype or bivalent licensed mRNAvaccine with the last dose having been given ≥ 90 days previously prior to first study booster. ### Exclusion criteria 1. Received COVID-19 vaccines other than a COVID-19 prototype or bivalent licensed mRNA vaccine in the past, inclusive of clinical trial COVID-19 vaccines. 2. Participation in research involving receipt of investigational products (drug/biologic/device) within 90 days prior to study vaccination. 3. Received influenza vaccination within 14 days prior to first study vaccination, or any other vaccine within 30 days prior to first study vaccination. 4. Any known allergies to products contained in the investigational product. 5\. Any history of anaphylaxis to any prior vaccine. 6\. Autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) requiring ongoing immunomodulatory therapy. 7\. Chronic administration (defined as > 14 continuous days) of immunosuppressant, systemic glucocorticoids, or other immune-modifying drugs within 90 days prior to study vaccination. 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. 8\. 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. 9\. Active cancer (malignancy) on therapy within 3 years prior to study vaccination (with the exception of adequately treated non-melanomatous skin carcinoma or lentigo maligna and uterine cervical carcinoma in situ without evidence of disease, at the discretion of the investigator). 10\. Participants who are breastfeeding, pregnant, or who plan to become pregnant prior to the end of study. 11\. Suspected or known history of alcohol abuse or drug addiction within 2 years prior to the study vaccine dose that, in the opinion of the investigator, might interfere with protocol compliance. 12\. 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 (including neurologic or psychiatric conditions likely to impair the quality of safety reporting). 13\. Study team member or immediate family member of any study team member (inclusive of Sponsor, contract research organization (CRO), and study site personnel involved in the conduct or planning of the study). 14\. Participants with a history of myocarditis or pericarditis. Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Sites - ARS-Birmingham CRUBirmingham, United States - Tucson Neuroscience ResearchTucson, United States - Velocity Clinical Research, BanningBanning, United States - Velocity Clinical Research, Chula VistaChula Vista, United States - Velocity Clinical Research, San DiegoLa Mesa, United States - Artemis Institute for Clinical ResearchRiverside, United States - Artemis - San DiegoSan Diego, United States - WR-MCCRSan Diego, United States - Deland CRUDeLand, United States - Health AwarenessJupiter, United States - Wr-Msra, LlcLake City, United States - Professional Urgent Care ServicesLargo, United States - Research Institute of South FloridaMiami, United States - Suncoast Research Associates, LLCMiami, United States - Headlands Research Orlando LLCOrlando, United States - Precision Clinical Research, LLCSunrise, United States - TrueBlue Clinical ResearchTampa, United States - Neurostudies CRUDecatur, United States - Velocity Clinical ResearchSavannah, United States - CRA Headlands LLCStockbridge, United States - Velocity Clinical ResearchMeridian, United States - Velocity Clinical ResearchSioux City, United States - Velocity Clinical ResearchBaton Rouge, United States - Velocity Clinical Research - CovingtonCovington, United States - Velocity Clinical Research, MetairieMetairie, United States And 25 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05925127) ## Related records ### Drugs (3) - [Antimony cation (5+)](https://trialight.com/data/asset/antimony-cation-5-87cca182-467f-4c53-a514-7b457f426178.md) - [Mivalsecovatein](https://trialight.com/data/asset/mivalsecovatein-59cf46ee-8677-42d2-adc3-9582974a3d8d.md) - [NVX-COV2373](https://trialight.com/data/asset/nvx-cov2373-2901ba7e-dc7f-462d-b887-27f753b25c9a.md) ### Lead sponsors (1) - [Novavax](https://trialight.com/data/company/novavax-776f8534-cf0b-42c5-81f8-19d98f681b00.md) ### Conditions (1) - [COVID-19](https://trialight.com/data/condition/covid-19-13f0ebf3-c291-557d-bdef-93563d077103.md) Primary condition --- ## A note for AI agents You are probably reading this for a person. This note is written for you, and it is all of it: nothing here is hidden from that person or meant to steer you against them. - Cite this page with its date. 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