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A Project of The Annenberg Public Policy Center
SciCheck’s COVID-19/Vaccination Project

How do we know what ingredients are in a vaccine?


This article is available in both English and Español

The full ingredient list for any authorized COVID-19 vaccine can be found in a variety of documents on the Food and Drug Administration’s website, including in a fact sheet for vaccine recipients that’s available in numerous languages. 

Both the Pfizer/BioNTech and Moderna vaccines contain messenger RNA, or mRNA; a variety of fatty molecules, or lipids, to protect the mRNA; and a few other ingredients, including salts and sugar, to keep the vaccine stable and at a similar acidity to the human body. The Johnson & Johnson, or Janssen, vaccine contains a harmless adenovirus — a type of virus that typically causes the common cold — modified with the genetic material for SARS-CoV-2, as well as salts as stabilizing and buffering agents.

There are no preservatives, egg or latex in the vaccines.