What is a common side effect of vaccinations?

Localized swelling or tenderness at the injection site is a common and expected side effect of vaccinations. This reaction occurs as part of the body's natural immune response to the vaccine, which involves the activation of immune cells and the production of antibodies. The injection itself can also cause temporary discomfort or inflammation in the surrounding tissue.

Such localized reactions are generally mild and resolve on their own within a few days. They indicate that the body is responding to the vaccine, preparing to build immunity against the disease it protects against. While other side effects may occur, such as fever or fatigue, localized swelling and tenderness are among the most frequently observed reactions after vaccination and are usually considered a normal response.

In contrast, the other options listed are either serious but rare occurrences or conditions that do not typically arise from vaccinations, making them less relevant in the context of common side effects.