Novavax COVID-19 Vaccine

by David Freedman last updated Apr 29, 2023 04:44 PM © Antimicrobial Therapy, Inc.
Nuvaxovid, Covovax, NVX-CoV2373


  • CDC vaccination recommendations updated as of April 19, 2023
  • Persons >12 yrs who previously received 1 or more doses of Novavax are recommended to receive 1 bivalent mRNA vaccine dose
  • Any bivalent mRNA vaccine may be used at 2 months to boost a primary series with Novavax, monovalent
  • See COVID-19, Vaccines for general vaccine indications, efficacy, duration of protection, choice an


  • Type: recombinant protein subunit vaccine, adjuvanted
  • Novavax COVID-19 Vaccine, Adjuvanted, monovalent (Nuvaxovid; Indian version branded as Covovax)
    • Contains same original strain spike protein that is coded for by mRNA vaccines

Dose and Schedule

  • Novavax remains authorized to provide:
    • A 2-dose primary series to people ages >12 years and older. The primary series doses are separated by 3–8 weeks. An 8-week interval between the first and second primary series doses might be optimal for some people ages 6 months–64 years, especially for males ages 12–39 years, as it might reduce the small risk of myocarditis and pericarditis associated with this vaccine.
    • A booster dose in limited situations to people ages 18 years and older who previously completed primary vaccination using any FDA-approved or FDA-authorized COVID-19 vaccine; have not received any previous booster dose(s); and are unable (i.e., mRNA vaccine contraindicated or not available) or unwilling to receive an mRNA vaccine and would otherwise not receive a booster dose. The monovalent Novavax booster dose is administered at least 6 months after completion of any primary series.
COVID-19 vaccination history Bivalent vaccine # of bivalent doses indicated Dosage (mL/ug) Interval between doses
1 or more doses of Novavax vaccine (5 µg rS and 50 µg of Matrix-M™ adjuvant) Moderna 1 0.5 mL/50 ug At least 8 weeks after last monovalent dose
Pfizer BioNTech 1 0.3 mL/30 ug At least 8 weeks after last monovalent dose
  • Additional bivalent dose. Persons >65 yrs have the option to receive 1 additional bivalent mRNA vaccine dose >4 mos after the first dose of a bivalent mRNA vaccine. If Moderna is used, administer 0.5 mL/50 ug (dark blue cap and label with a gray border); if Pfizer-BioNTech is used, administer 0.3 mL/30 ug (gray cap and label with a gray border).



  • Anaphylaxis or immediate allergic reaction (within 4h) to a previous dose of an mRNA vaccine or separately to a vaccine constituent including polyethylene glycol (PEG) or polysorbate. 
    • Do not vaccinate with any mRNA vaccine
  • History of a known diagnosed allergy to a vaccine component


  • Immediate allergic reaction (within 4h) to any other vaccine or injectable therapy not related to a component of mRNA-COVID-19 vaccines or polysorbate.
  • Persons with a reaction to a vaccine or injectable therapy that contains PEG
  • History of myocarditis or pericarditis after a dose of an mRNA or Novavax COVID-19 vaccine, avoid future doses of any COVID-19 vaccine
  • Allergy-related contraindication to one type of COVID-19 vaccine is a precaution to the other types of COVID-19 vaccines
  • Defer vaccination until resolution of a moderate or severe acute illness, with or without fever

Not Contraindications

  • Food (including egg and gelatin), pet, insect, venom, environmental, latex, oral medications; any other history of anaphylaxis not related to vaccine or injectables.
  • History of GBS in proximity to another vaccine.

Adverse Effects

  • Pain at the injection site, sometimes severe, occurs frequently
  • Fatigue, headache, and myalgia common but are mild to moderate, occurring within 1–3 days of vaccination, and resolving within 1–3 days of onset.
    • More frequent following dose 2 and among ages 12–64 years compared to >65 years
  • Myocarditis: cases identified in clinical trials and post-authorization. risk low but as yet unquantified. 
    • Reactions more frequentand after dose 2 than dose 1.
    • 8-week interval between the first and second primary series doses of Moderna, Novavax, and Pfizer-BioNTech COVID-19 vaccines may be optimal for some people to reduce myocarditis.

Special Populations


  • Vaccinate according to standard recommendations if pregnant, breastfeeding, attempting or contemplating conception
    • Pregnant and recently pregnant persons at increased risk for severe illness and the fetus is at increased risk
  • Benefits outweighs risks of vaccination
  • Antibodies are transferred to the newborn
  • No contraindications to breastfeeding

Immunocompromised / HIV

  • An updated vaccine schedule table for immunocompromised person will be published shortly by CDC

Serologic Testing

  • Antibody testing is not recommended to assess for immunity following COVID-19 vaccination or to assess the need for vaccination in an unvaccinated person.
  • No correlates of protection are available and assays vary widely.
  • +ve IgG only minimally reassuring, -ve IgG unhelpful in patients whose ability to mount a B-cell response is uncertain.
  • If antibody testing is done, vaccination should be completed as recommended regardless of the antibody test result.
  • Prior receipt of a COVID-19 vaccine will not affect the results of SARS-CoV-2 viral tests (nucleic acid amplification or antigen tests).