(ABC4 News) — Have you ever wondered what medical concoction makes up a vaccine? Well, when you look at a few ingredients contained in a vaccine they might not look that different from your favorite cookie recipe. Ingredients like sugar, salt, and eggs are commonly found in vaccines.

First things first, what is a vaccine? A vaccine is a way to exchange your body’s natural defense against a disease without actually causing you to have the illness. 

Vaccines have been used for over 200 years to safely decrease and eradicate certain diseases that previously harmed or killed millions of people. They help the body develop immunity by training the immune system to recognize and remember how to respond to the disease-causing part of a virus. Traditionally, vaccines contain either weakened or inactivated (killed) viruses.

According to the Centers for Disease Control and Prevention, CDC, vaccines used today use ingredients that are safe and effective. Each ingredient in the vaccine serving a specific purpose.

**The below information on ingredients commonly used in vaccines is from the CDC.

Adjuvants: Aluminum salts

Adjuvants are used to help boost the body’s response to the given vaccine. Aluminum salts are commonly found in drinking water, infant formula, or used in health products such as antacids, buffered aspirin, and antiperspirants

Preservatives: Thimerosal, only used in multi-dose vials of the flu vaccine.

They’re in our food and in our vaccines. They are added to vaccines to prevent contamination. You can come in contact with these kinds of preservatives by eating certain kinds of fish.

Stabilizers: Sugars and gelatin

Stabilizers like sugars and gelatin are used in vaccines to keep them effective after the vaccine is manufactured. You would find sugars and gelatin used in vaccines in food like Jell-o.

Residual cell culture materials: Egg protein

Egg protein is used in vaccines to grow enough of the virus or bacteria to make the vaccine.

The CDC says vaccines like the ones for influenza and yellow fever are made in eggs so egg protein is present in the final products. People who have severe egg allergies should be vaccinated in a medical setting and be supervised by a health care professional who can recognize and manage severe allergic conditions. There are also two new flu vaccines available for people with egg allergies.

Residual inactivating ingredients: Formaldehyde

Formaldehyde is used in vaccines to kill viruses or inactivate toxins during the manufacturing process. Formaldehyde resides in the body naturally. There is more formaldehyde in your body than vaccines.

Residual antibiotics: Neomycin

Neomycin is used in vaccines to prevent contamination by bacteria during the vaccine manufacturing process. Antibiotics that many people are allergic to, such as penicillin aren’t used in vaccines.

According to the CDC, over billions of doses of vaccines are manufactured worldwide each year and given to healthy babies, children, and adults.

The U.S. Food & Drug Administration, FDA, says prior to vaccine approval, as part of FDA’s evaluation, all of the ingredients of a vaccine are taken into account, including the active ingredients as well as other substances.