evidence: People who've had a severe allergic reaction to any of the vaccine's ingredients or after a prior dose of a Pfizer-BioNTech vaccine shouldn't get the vaccine. [...] Pfizer-BioNTech COVID-19 vaccine. U.S. Food and Drug Administration. https://www.fda.gov/vaccines-blood-biologics/coronavirus-covid-19-cber-regulated-biologics/pfizer-biontech-covid-19-vaccine. Accessed Nov. 7, 2023.