NCT05973006

Phase 3 Adolescent Study for SARS-CoV-2 rS Variant Vaccines

A Phase 3, Randomized, Double-Blinded Study to Evaluate the Safety and Immunogenicity of Omicron Subvariant and Bivalent SARS-CoV-2 rS Vaccines in Adolescents Previously Vaccinated With mRNA COVID-19 Vaccines

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 400 (actual)
• Sponsor: Novavax · Industry
• Sex: All
• Age: 11 Years – 18 Years
• Healthy volunteers: Accepted

Summary

This study is a large-scale investigation (Phase 3) into a new booster shot designed specifically for teenagers. The booster targets a particular variant of COVID-19, Omicron XBB.1.5. The main focus is on safety: researchers want to see if this new booster is safe for teenagers who have already received two doses of the Pfizer or Moderna mRNA COVID-19 vaccines. To ensure a fair comparison, the study will use a double-blind approach. This means two groups of teenagers will receive booster shots, but neither the teenagers nor the researchers giving the shots will know beforehand which version of the booster each person gets. The study will also assess how well the body fights the virus after the booster shot.

Detailed description

This is a Phase 3, randomized, double-blinded study to evaluate the safety and immunogenicity of booster doses of Omicron subvariant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant (r) spike (S) protein nanoparticle vaccines (SARS-CoV-2 rS) adjuvanted with Matrix-M™ adjuvant (NVX-CoV2601 \[Omicron XBB.1.5\]) and bivalent (NVX-CoV2373 \[prototype\] + NVX CoV2601) in previously vaccinated adolescent participants ≥ 12 to \< 18 years of age. Approximately 400 adolescents who have received a regimen of ≥ 2 doses of the Moderna and/or Pfizer-BioNTech monovalent and/or bivalent COVID-19 vaccines ≥ 90 days previously will be randomized 1:1 to Group A or Group B: * Group A: 1 dose of NVX-CoV2601 (1 on Day 0) * Group B: 1 dose of bivalent NVX-CoV2373 + NVX-CoV2601 (1 on Day 0) All participants will remain on study for immunogenicity and safety data collection through Day 180.

Conditions

• COVID-19

Interventions

Type	Name	Description
BIOLOGICAL	NVX-CoV2601 co-formulated Omicron XBB.1.5 SARS-CoV-2 rS vaccine	Coformulated Omicron XBB.1.5 SARS-CoV-2 rS vaccine with Matrix-M adjuvant: supplied as a solution for preparation for injection, at a concentration of 10 µg antigen and 100 µg adjuvant per mL. All injections will be administered in a 0.5 mL injection volume at a dose of 5 µg antigen with 50 µg Matrix-M adjuvant.
BIOLOGICAL	Prototype/XBB.1.5 Bivalent Vaccine (5 µg)	A site-mixed bivalent vaccine prepared by combining 0.25 mL of NVX-CoV2373 and 0.25 mL NVX-CoV2601. All injections will be administered in a 0.5 mL injection volume at a dose of 5 µg total antigen (2.5 µg prototype antigen + 2.5 µg Omicron XBB.1.5 antigen) with 50 µg Matrix-M adjuvant.

Timeline

• Start date: 2023-08-16
• Primary completion: 2024-04-01
• Completion: 2024-09-30
• First posted: 2023-08-02
• Last updated: 2025-07-15
• Results posted: 2025-07-15

Locations

20 sites across 1 country: United States

Regulatory

• FDA-regulated drug study