What is Nuvaxovid (NVX‑CoV2373) COVID‑19 vaccine?

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Last updated: September 18, 2026 • View editorial policy

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What is Nuvaxovid?

Nuvaxovid (NVX-CoV2373) is an FDA-approved protein-based COVID-19 vaccine containing recombinant SARS-CoV-2 spike protein nanoparticles formulated with Matrix-M adjuvant, indicated for active immunization against COVID-19 in individuals 65 years and older, or those 12-64 years with high-risk conditions for severe disease. 1

Vaccine Composition and Mechanism

Nuvaxovid differs fundamentally from mRNA vaccines by using a traditional protein-based platform. The vaccine contains:

  • Recombinant SARS-CoV-2 spike (rS) protein arranged as trimeric nanoparticles
  • Matrix-M saponin-based adjuvant to enhance immune response
  • Does not contain live SARS-CoV-2 virus and cannot cause COVID-19 1

This protein-based approach offers an alternative for individuals hesitant about or unable to receive mRNA vaccines 2.

Current FDA Approval Status (2025-2026 Formula)

The 2024-2025 formulation is based on the JN.1 strain and received FDA Emergency Use Authorization on August 30,2024 3. The vaccine is:

  • FDA-approved for ages ≥65 years
  • Approved for ages 12-64 years with at least one high-risk condition for severe COVID-19
  • Administered as a 0.5 mL intramuscular injection 1

ACIP Recommendations for Use

For Previously Unvaccinated Individuals ≥12 Years:

  • Requires 2 doses given 3-8 weeks apart (unlike mRNA vaccines which require only 1 dose for previously unvaccinated adults) 3

For Previously Vaccinated Individuals:

  • 1 dose of 2024-2025 Nuvaxovid given ≥8 weeks after last COVID-19 vaccine dose 3

For Immunocompromised Individuals ≥12 Years:

  • Unvaccinated: 2 doses of 2024-2025 Nuvaxovid
  • Previously vaccinated: Follow standard recommendations with potential for additional doses 3

Important caveat: Nuvaxovid is NOT authorized for children aged 6 months-11 years—only Moderna and Pfizer-BioNTech mRNA vaccines are available for this age group 3.

Efficacy Profile

Clinical trial data demonstrates:

  • 90.4% efficacy against symptomatic COVID-19 (95% CI: 82.9-94.6%) 4
  • 100% efficacy against moderate-to-severe disease (95% CI: 87.0-100%) 4
  • 92.6% efficacy against variants of concern including Alpha variant (95% CI: 83.6-96.7%) 4
  • Durable protection with evidence of waning: 88% efficacy at 40 days declining to 77% at 180 days against Delta variant 5

The vaccine induces both humoral (antibody) and cellular (CD4+ and CD8+ T cell) immune responses 6.

Safety Profile

Real-world safety data from over 100,000 doses shows 7:

Common Reactions (Mostly Mild-to-Moderate):

  • Local reactions in 76% of recipients: pain/tenderness, swelling, redness, itching at injection site
  • Systemic reactions in 70%: fatigue, muscle pain, headache, joint pain, nausea, fever, chills
  • Grade 3+ reactions occur in 6.28% (local) and 11.36% (systemic) 8
  • Reactions more frequent after dose 1 than dose 2, and in females vs males 7

Serious Adverse Events:

  • Myocarditis and pericarditis reported but very rare (myocarditis rate: 1.9 per 100,000 doses; pericarditis: 19.4 per 100,000 doses) 7
  • Chest pain reported in 91.3 per 100,000 doses 7
  • Severe allergic reactions possible but rare
  • Overall serious adverse event rate: 0.91% (comparable to placebo at 1.0%) 8

Critical safety consideration: Seek immediate medical attention for signs of myocarditis/pericarditis (chest pain, shortness of breath, palpitations) or severe allergic reaction (difficulty breathing, facial swelling, fast heartbeat, severe rash, dizziness) 1.

Contraindications

Do not administer Nuvaxovid if the individual had:

  • Severe allergic reaction to a previous dose of Nuvaxovid or Novavax COVID-19 vaccine
  • Severe allergic reaction to any vaccine ingredient 1

Storage and Administration

  • Supplied as pre-filled syringes (0.5 mL single dose)
  • Store refrigerated at 2°C to 8°C (36°F to 46°F)
  • Protect from light; do not freeze 1

Clinical Context

Nuvaxovid provides a protein-based alternative that may address vaccine hesitancy and offers comparable protection to mRNA vaccines. The 2-dose requirement for unvaccinated individuals ≥12 years is a key distinguishing feature from current mRNA vaccine recommendations 3. Real-world data from immunocompromised populations shows similar infection risk reduction compared to non-immunocompromised individuals, supporting its use across diverse patient populations 9.

References

5
Research

Durability of Protection Against COVID-19 Through the Delta Surge for the NVX-CoV2373 Vaccine.

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2024

7
Research

Nuvaxovid NVX-CoV2373 vaccine safety profile: real-world data evidence after 100,000 doses, Australia, 2022 to 2023.

Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 2024

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.