The least common and most severe reaction to a vaccine is

Question

Quizplus · Accepted Answer

An allergic reaction is the least common but most severe reaction to a vaccine. This can manifest as anaphylaxis, which is a life-threatening reaction that can cause difficulty breathing, rapid heartbeat, and loss of consciousness. Local reactions refer to redness or pain at the injection site, while systemic reactions may include fever or fatigue. Idiosyncratic reactions are unpredictable and rare, and can vary widely in their symptoms.

The Least Common and Most Severe Reaction to a Vaccine