What is a contraindication for receiving a COVID-19 vaccination?

A known (diagnosed) allergy to a component of a COVID-19 vaccine is considered a contraindication because it indicates that the individual may have a severe allergic reaction to the vaccine. Vaccines contain various components, such as preservatives, stabilizers, and active ingredients, and some individuals may have sensitivities or allergies to these substances. In the context of vaccination, an allergic reaction could potentially lead to serious outcomes, such as anaphylaxis. Therefore, people with a documented allergy to a specific component of a COVID-19 vaccine should not receive that vaccine to avoid serious health risks.

Other options do not represent absolute contraindications; for instance, receiving a COVID-19 vaccine on the same day as an influenza vaccination is generally acceptable and has been recommended by health authorities. Additionally, former allergic reactions to other vaccines do require a careful assessment, but they do not automatically disqualify someone from receiving a COVID-19 vaccination unless the reaction was severe. The mention of a contraindication to mRNA vaccines while requesting the Janssen vaccine points to a need for alternative vaccination options, not a blanket prohibition against vaccination altogether. Thus, the critical factor remains any diagnosed allergy to a vaccine component, parameter that warrants withholding the vaccine for the safety of the individual.