Components of Vaccines

Updated April 6, 2023

Vaccines are made with a variety of ingredients including antigens, stabilizers, adjuvants, and preservatives; they may also contain residual by-products from the production process. Knowing precisely what is in each vaccine can be helpful when investigating adverse events following vaccination and for choosing alternative products for persons who have allergies or have had an adverse event known or suspected to be related to a vaccine component.

Since package inserts can change and there are sometimes small modifications in the components, the most recent package inserts (links available on the Package Inserts page) should be reviewed to verify specific information.

Below are links to tables organized by Excipients, Allergens, and Vaccine Type.

Excipients Page

Allergens Page