Ingredients in a Vaccine

Vaccines help the body develop immunity to viruses and germs by introducing the body to a less harmful part of germs or something created to act like it, so the body’s immune system develops antibodies to fight that particular germ.

Later, if a person encounters that harmful germ again, their immune system can remember how to fight it off and either prevent infection entirely or reduce the severity of the disease. This process helps prevent people from getting sick.

What ingredients are in a vaccine?

Vaccines contain a variety of ingredients that are needed to keep the vaccine as safe and effective as possible, according to the Centers for Disease Control and Prevention (CDC). Each ingredient serves a specific purpose:

• provide immunity from the associated virus or germ
• keep the vaccine safe and long-lasting
• used for the production of the virus.

Vaccines can contain:

• Aluminum Salts: to help boost the body’s response to the vaccine
• Sugars, Gelatin: to keep the vaccine effective after manufactured
• Egg Protein: to grow enough of the virus or bacteria to make the vaccine
• Residual Inactive Ingredients: to kill viruses or inactivate toxins during manufacturing

“Vaccines are made thoughtfully – only including the pieces needed to help provide immunity for the disease, to ensure distribution and a longer shelf life of the dose, and to keep the vaccine as safe as possible,” explained Dr. Maryrose Laguio-Vila, Infectious Disease Specialist at Rochester Regional Health.

What are the ingredients of the COVID-19 vaccines?

According to the US Food and Drug Administration, the below is the list of ingredients for the Pfizer/BioNTech vaccine, available for distribution in the United States:

• Active Ingredient
• nucleoside-modified messenger RNA (modRNA) encoding the viral spike glycoprotein (S) of SARS-CoV-2
• Lipids
• (4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis (ALC-3015)
• (2- hexyldecanoate),2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide (ALC-0159)
• 1,2-distearoyl-snglycero-3-phosphocholine (DPSC)
• cholesterol
• Salts
• potassium chloride
• monobasic potassium phosphate
• sodium chloride
• basic sodium phosphate dihydrate 
• Other
• sucrose

“The active ingredient in the Pfizer/BioNTech COVID-19 Vaccine is messenger RNA, or mRNA, a type of molecule whose job is to transport copies of the code for cells to make the proteins specific to the coronavirus, helping your body to create antibodies,” says Dr. Laguio-Vila.

Next, are the lipid molecules, a small ball of fat that protect the mRNA. This protective ball is very fragile, which is why the vaccines need to be stored at subzero temperatures. The salts help keep the pH of the vaccine balanced, keep the lipids and mRNA protected and help your body absorb the solution. The sucrose (sugar) protects the vaccine during freezing.

Many ingredients in vaccines are produced naturally by the body and are found in common foods, beverages, and medications like fish, eggs, water, infant formula, aspirin, and antacids.

Read more on Vaccines from the Center for Disease Control