The Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) on Wednesday signed off on Novavax's COVID-19 vaccine to use as a first booster dose for people aged 18 and older.
The shot "contains the SARS-CoV-2 spike protein and Matrix-M adjuvant," the FDA said, referring to the virus that causes COVID-19. "Adjuvants are incorporated into some vaccines to enhance the immune response of the vaccinated individual. The spike protein in this vaccine is produced in insect cells; the Matrix M-adjuvant contains saponin extracts from the bark of the Soapbark tree that is native to Chile."
Specifically, the vaccine is based on an older technology that has been used for decades to combat diseases including hepatitis B and influenza.
The company previously said it developed the vaccine for people who are hesitant to receive the Moderna, Pfizer, or Johnson & Johnson shots.
Previously, the Novavax vaccine was used only as a two-dose primary series after the FDA and CDC signed off on it in July. It is the fourth coronavirus vaccine available in the United States, and unlike the others, it uses a protein-based technology.
Other than in the United States, Novavax has been approved in Canada, South Korea, New Zealand, the European Union, Taiwan, Israel, and the United Kingdom.
Novavax, however, has been struggling to boost sales of the vaccine and in August halved its full-year revenue forecast, saying it does not expect further sales of the shot in the United States this year.
Only around 35,000 doses of the vaccine have been administered across the United States so far since the company originally got the regulator's nod in July, as per CDC data. However, over half the population in the United States eligible for a booster has yet to take one, according to the data.