COVID-19 vaccine ingredients and their purpose

JACKSON, Miss. (WLBT) - The Centers for Disease Control and Prevention (CDC) says each ingredient in any vaccine serves a specific purpose to provide immunity and keep the vaccine safe and long-lasting.

Here’s what’s inside the popular Pfizer and Moderna vaccines, according to the Food and Drug Administration (FDA).

The Pfizer-BioNTech COVID-19 Vaccine includes the following ingredients: mRNA, lipids ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol), potassium chloride, monobasic potassium phosphate, sodium chloride, dibasic sodium phosphate dihydrate, and sucrose.

The Moderna COVID-19 Vaccine contains the following ingredients: messenger ribonucleic acid (mRNA), lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG], cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC]), tromethamine, tromethamine hydrochloride, acetic acid, sodium acetate, and sucrose.

Here are the main ingredients, examples, purpose, and most common source of any vaccine, according to the CDC.

Type of Ingredient	Example(s)	Purpose	Most common source found…
Preservatives	Thimerosal (only in multi-dose vials of flu vaccine)*	To prevent contamination	From eating foods such as certain kinds of fish, mercury (which thimerosal contains) gets into the body
Adjuvants	Aluminum salts	To help boost the body’s response to the vaccine	From drinking water, infant formula, or use of health products such as antacids, buffered aspirin, and antiperspirants
Stabilizers	Sugars, gelatin	To keep the vaccine effective after manufactured.	From eating food such as Jell-O® and resides in body naturally
Residual cell culture materials	Egg protein^	To grow enough of the virus or bacteria to make the vaccine	From eating foods containing eggs
Residual inactivating ingredients	Formaldehyde†	To kill viruses or inactivate toxins during the manufacturing process	Resides in body naturally (more in body than vaccines). Also found automobile exhaust, and household furnishing such as carpets and upholstery.
Residual antibiotics	Neomycin	To prevent contamination by bacteria during the vaccine manufacturing process	Antibiotics that people are most likely to be allergic to — like penicillin — aren’t used in vaccines

The CDC is also administering mRNA, a new type of vaccine to protect against infectious diseases. To trigger an immune response, many vaccines put a weakened or inactivated germ into our bodies, but not mRNA vaccines.

“COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the ‘spike protein.’ The spike protein is found on the surface of the virus that causes COVID-19,” the CDC says.

COVID-19 mRNA vaccines are given in the upper arm muscle. Once the instructions (mRNA) are inside the immune cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them. Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn’t belong there and begin building an immune response and making antibodies.