Additives & Excipients

Additives are used in the manufacture of vaccines to prevent changes in the solution under adverse conditions, such as freeze-drying or heat. They help to prevent the antigens from adhering to the side of the vial. Vaccines also contain several reagents that are derived from animals.

Excipients are considered to be pharmacologically inactive substances used as a carrier for the active ingredients. In many cases, an “active” substance is mixed with an excipient to be more easily absorbed into the body. Even though they are considered to be inert - they often are NOT, and can have metabolic interactions.

Johns Hopkins maintains a full, updated list of vaccine excipients which can change from time to time.