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This is one of the COVID-19 vaccines. 


Active ingredients:

This is a recombinant protein subunit vaccine. The active ingredient is a recombinant version of the spike protein. Because the active ingredient is just the spike protein (not the whole virus), you cannot get COVID-19 from the vaccine. 

The active ingredient (recombinant spike protein) is produced using a viral vector. The genetic information to make the spike protein is inserted into the genome of baculovirus, which is a kind of virus that infects insects but is harmless to humans. Then, the baculovirus (with genetic information to make the spike protein) is used to infect cells from Spodoptera frugiperda, which is a type of moth. As the baculovirus replicates in the moth cells, it makes the spike protein, which is purified and used as the active ingredient. 

This vaccine also contains an adjuvant called Matrix-M, which contains saponin extracts from the soapbark tree, Quillaja saponaria Molina. Saponins are a type of compound found in foods such as legumes (peanuts, beans, etc.). Saponins from the soapbark tree have also been shown to have anti-cancer effects.

This vaccine does not contain preservatives, eggs, polyethylene glycol, or aluminum.

Inactive ingredients:
Amounts are based on a 0.5 mL dose

Salts: help maintain the stability and pH of the vaccine

Lipids: A type of compound that does not dissolve in water. They are used to create a protective coating around the active ingredient. This coating is also called a liposome.
Amounts are not listed in the package insert, but both of these compounds are naturally in almost every cell in the body.


To adjust the pH, the vaccine may contain sodium hydroxide (NaOH) or hydrochloric acid (HCl). NaOH is a strong base, which means that it increases the pH and makes a solution less acidic. HCl is a strong acid, so it lowers the pH and makes a solution more acidic. pH adjustment is used to increase the stability of the vaccine.

Relevant Terms

  • Adjuvant: a compound added to some vaccines to strengthen the immune response

  • Antibody: a protein made by the immune system in response to a foreign particle (antigen). These proteins circulate in the blood and help defend the body against the substance.

  • Antigen: This is any substance that triggers the immune system to create antibodies. For example, allergens such as pollen are antigens.

  • Lipids: substances that do not mix with water such as fats, hormones, waxes, and oils

  • pH: a measure of how acidic or basic a solution is. The scale ranges from 0 (very acidic) to 14 (very basic). A pH of 7 is neutral.

  • Recombinant Protein: a protein that is made by putting genetic information into the genome of another species. That species makes the protein, which is isolated and purified. 

  • Spike protein: the protein in SARS-CoV-2 that allows the virus to recognize and attach to host cells.

  • Viral vector: a version of a virus that has been modified to contain genetic information from another source (in this case, the genetic information to make the spike protein). 

Relevant terms


Last updated: Feb. 18, 2023

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