We’ve all been looking forward to having a vaccine against COVID-19. Now that it’s finally here, many of us want to know more about what’s in it. But in order to understand its components, let us first breakdown the common ingredients of vaccines and why these ingredients are necessary.
As most people may know, vaccines contain tiny fragments of the disease-causing organism or the blueprints for making the tiny fragments. However, they also contain other ingredients to keep the vaccine safe and effective. These latter ingredients are included in most vaccines and have been used for decades in billions of doses of vaccine.
Today’s vaccines use only the ingredients they need to be safe and effective. Each vaccine component serves a specific purpose, and each ingredient is tested in the manufacturing process. All ingredients are tested for safety. For example, vaccine ingredients may:
- Help provide immunity (protection) against a specific disease
- Help keep the vaccine safe and long lasting
- Be used during the production of the vaccine
But let’s get down to specifics. The following are the ingredients commonly used in vaccines:
Antigen
All vaccines contain an active component (the antigen) which generates an immune response, or the blueprint for making the active component. The antigen may be a small part of the disease-causing organism, like a protein or sugar, or it may be the whole organism in a weakened or inactive form.
Preservatives
Preservatives prevent the vaccine from becoming contaminated once the vial has been opened, if it will be used for vaccinating more than one person. Some vaccines don’t have preservatives because they are stored in one-dose vials and are discarded after the single dose is administered. The most commonly used preservative is 2-phenoxyethanol. It has been used for many years in a number of vaccines, is used in a range of baby care products and is safe for use in vaccines, as it has little toxicity in humans.
Stabilizers
Stabilizers prevent chemical reactions from occurring within the vaccine and keep the vaccine components from sticking to the vaccine vial.
Stabilizers can be sugars (lactose, sucrose), amino acids (glycine), gelatin, and proteins (recombinant human albumin, derived from yeast).
Surfactants
Surfactants keep all the ingredients in the vaccine blended together. They prevent settling and clumping of elements that are in the liquid form of the vaccine. They are also often used in foods like ice cream.
Residuals
Residuals are tiny amounts of various substances used during manufacturing or production of vaccines that are not active ingredients in the completed vaccine. Substances will vary depending on the manufacturing process used and may include egg proteins, yeast or antibiotics. Residual traces of these substances which may be present in a vaccine are in such small quantities that they need to be measured as parts per million or parts per billion.
Diluent
A diluent is a liquid used to dilute a vaccine to the correct concentration immediately prior to use. The most commonly used diluent is sterile water.
Adjuvant
Some vaccines also contain adjuvants. An adjuvant improves the immune response to the vaccine, sometimes by keeping the vaccine at the injection site for a little longer or by stimulating local immune cells.
The adjuvant may be a tiny amount of aluminum salts like aluminum phosphate, aluminum hydroxide or potassium aluminum sulphate. Aluminum has been shown not to cause any long-term health problems, and humans ingest aluminum regularly through eating and drinking.
What are the coronavirus (COVID-19) vaccines made of?
The key ingredient in COVID-19 vaccines is the genetic material (mRNA) that holds the genetic code of COVID-19. This genetic code is then wrapped in oil packets or tiny bubbles of lipid (oil) to surround and protect the mRNA so cells in your body can pick it up. Finally, COVID-19 vaccines also contains saline solution, which is essentially salts and sugar dissolved in water. It is often used in vaccines, medications, and solutions containing living cells. It holds the pH and salt levels of the mixture close to that of our bodies, so the injection will be more comfortable when we receive it.
Each company producing the vaccines made tiny changes to the genetic sequence of the mRNA that they used so the vaccines would produce a stronger immune response.
What we need to remember
At the small doses planned for the COVID-19 vaccines, none of the chemicals mentioned are expected to be toxic or dangerous. mRNA by itself is not dangerous. In fact, there is mRNA inside the cells of all plants and animals.
The vaccines were able to be developed quickly because a lot of the companies creating vaccines were already studying mRNA to make vaccines and medications against other diseases. Because of this, there is a great deal of research about all of the ingredients in COVID-19 vaccines that are in peer-reviewed scientific literature.
The COVID-19 vaccines do not contain live virus, inactivated virus, or preservatives. The genetic material in the COVID-19 vaccines falls apart naturally in a few days, after your body has had time to make antibodies against the SARS-CoV2 spike proteins.
Author: Alona Estanilla Teo
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