The Centers for Disease Control and Prevention (CDC) has recommended that Novavax’s COVID-19 vaccine be used as another primary series option for adults in the United States ages 18 years and older.
The Food and Drug Administration (FDA) previously authorized for emergency use the protein-based vaccine, known as NVX-CoV2373.
The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health; the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response; the Department of Defense (DoD) Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND); and the Defense Health Agency supported the development of NVX-CoV2373 as part of the U.S. government’s rapid response to develop safe and effective COVID-19 vaccines.
DoD funded the early development of technology used in the NVX-CoV2373 vaccine, and NIAID, BARDA, JPEO-CBRND and DoD provided support for clinical trials evaluating its safety and efficacy. BARDA also provided funding and expertise to support manufacturing and procurement of the vaccine.
NVX-CoV2373 contains a stabilized form of the SARS-CoV-2 spike protein—a surface protein that facilitates entry to human cells. The approach for stabilizing the spike protein was invented by NIAID scientists and their collaborators. The spike proteins are organized in tiny protein particles called nanoparticles. The vaccine is formulated with a saponin‐based adjuvant. Saponins are naturally occurring compounds from soapbark trees. Adjuvants are sometimes added to vaccines to enhance immune responses.
The U.S. government supported the Phase 3 clinical trial known as PREVENT-19 that enrolled 29,960 adult participants in the United States and Mexico between Dec. 27, 2020, and Feb. 18, 2021. Participants were randomly assigned to receive two doses of the candidate vaccine 21 days apart or two injections of a saline placebo. Randomization occurred in a 2:1 ratio, with two volunteers receiving NVX-CoV2373 for each one who received placebo. Results published in the New England Journal of Medicine showed the candidate vaccine was 90.4% effective in preventing symptomatic COVID-19 among trial participants and 100% effective in preventing moderate-to-severe COVID-19. The trial was conducted before the Omicron variant of SARS-CoV-2 became dominant.
The PREVENT-19 trial expanded in May 2021 to enroll adolescents ages 12 to 17 years. Novavax has noted that the trial results in adolescents demonstrated comparability to those observed in the adult population. PREVENT-19 also is evaluating a third shot or booster dose in both adult and adolescent participants. In addition, NIAID is studying NVX-CoV2373 in the Phase 1/2 “mix & match” trial, in which adult volunteers who have been fully vaccinated against COVID-19 receive booster doses of different COVID-19 vaccines to determine the safety and immunogenicity of mixed boosted regimens.