The Novavax COVID vaccine could soon receive full approval from the U.S. Food and Drug Administration (FDA), the company said April 23.
The update sent Novavax’s stock up more than 21% in early trading. It also helped ease fears that the decision had been delayed by the Trump Administration, the Associated Press reported.
Novavax makes the only protein-based COVID-19 vaccine that’s still available in the United States. Right now, it is only approved under emergency use. That’s different from the mRNA vaccines from Pfizer and Moderna, which have full FDA approval for certain age groups.
In a new statement, Novavax said the FDA has asked the company to collect more clinical data from people who receive its shot.
The company added that it is “engaging with the FDA expeditiously” in hopes of getting full approval “as soon as possible.”
Under emergency use, vaccines can be removed even after a health emergency is considered to be over. Full approval from the FDA means a product can stay on the market even after a health emergency ends. (The World Health Organization declared an end to the COVID-19 emergency in May 2023.)
The vaccine was on track for FDA approval by April 1. However, acting FDA Commissioner Dr. Sara Brenner told the agency to pause the decision, the AP said.
This sparked concerns that U.S. Health Secretary Robert F. Kennedy Jr., a longtime vaccine skeptic, may have influenced the delay. FDA vaccine chief Dr. Peter Marks stepped down last month after clashing with Kennedy over vaccine safety.
The COVID vaccines used in the U.S. train the body to recognize the tell-tale spike protein on the SARS-CoV-2 virus.
Unlike the Pfizer and Moderna vaccines, which rely on a genetic code to trigger an immune response, Novavax’s vaccine combines lab-grown copies of the spike protein with an agent that helps boost the immune system.
Each year, vaccine makers update their COVID-19 shots to better target new variants, much like how flu shots are changed yearly.
What is Novavax?
Novavax, Inc., an American biotechnology company headquartered in Gaithersburg, Maryland, has been a significant player in the development of vaccines against serious infectious diseases. Before 2020, Novavax focused on creating experimental vaccines for influenza, respiratory syncytial virus (RSV), Ebola, and other emerging infectious diseases. However, the onset of the COVID-19 pandemic led the company to redirect its efforts toward developing and gaining approval for its COVID-19 vaccine, NVX-CoV2373.
How does the Novavax COVID vaccine work?
The Novavax COVID-19 vaccine is a protein subunit vaccine, a more traditional approach compared to the mRNA technology used in some other COVID-19 vaccines. It works by introducing a lab-made version of the SARS-CoV-2 spike protein into the body.3 This spike protein mimics the structure of the actual virus but cannot replicate or cause the disease.
How was the Novavax COVID vaccine created?
The creation of the Novavax vaccine involves several key steps. First, Novavax scientists use genetic engineering techniques to produce large quantities of the SARS-CoV-2 spike protein. They insert the genetic material of the spike protein into insect cells (specifically, fall armyworm cells infected with baculovirus), which then act as miniature factories to produce the protein. These proteins are then harvested and purified.
The final vaccine contains these purified spike proteins, assembled into nanoparticles, along with their proprietary Matrix-M adjuvant and other ingredients like cholesterol, phospholipids, and salts to ensure stability and proper delivery. When the vaccine is injected, typically into the deltoid muscle of the upper arm, the immune system recognizes the spike protein as foreign. The adjuvant helps to amplify this recognition, prompting the body to produce antibodies and T-cells that are specifically targeted against the SARS-CoV-2 spike protein. As a result, if the vaccinated individual is later exposed to the actual virus, their immune system is primed to recognize and fight it off, thus preventing or reducing the severity of COVID-19.
Was the Novavax COVID vaccine tested?
Clinical trials involving tens of thousands of participants demonstrated the efficacy of the Novavax COVID-19 vaccine in preventing symptomatic COVID-19. Furthermore, studies indicated a high level of protection against moderate to severe illness and hospitalization from the virus strains circulating during the trials. The vaccine has since been authorized for use in adults and adolescents in various countries and has been updated to address emerging variants like Omicron JN.1 for the 2024-2025 formulations. While generally well-tolerated, common side effects include injection site reactions, fatigue, headache, and muscle pain. Rare side effects like myocarditis and pericarditis have also been reported.18
More information
Learn more about Novavax on its website.
SOURCE: Associated Press, April 23, 2025