Vaccine contraindications

The CDC says the two mRNA COVID-19 vaccines authorized in the U.S. are contraindicated in people with a history of the following: severe allergic reaction after prior receipt of an mRNA COVID-19 vaccine or its components; allergic reaction (of any severity) immediately after receipt of an mRNA COVID-19 vaccine or its components, including polyethylene glycol; or immediate allergic reaction (of any severity) to polysorbate. The CDC notes that polysorbate and polyethylene glycol are structurally related, raising concerns about cross-reactive hypersensitivity between the two. People meeting the above criteria should not receive either mRNA COVID-19 vaccine unless an allergist-immunologist determines they can do safely — for example, in a setting where they are observed after vaccination and advanced medical care is accessible.

CDC’s vaccine contraindications