What is a potential side effect of the Hepatitis B vaccination?

The potential side effect of the Hepatitis B vaccination that is highlighted here is pain at the injection site. This is a common and generally mild reaction that can occur following vaccinations, including those for Hepatitis B. The pain may manifest as soreness, tenderness, or slight swelling in the area where the vaccine was injected. Such reactions are typically temporary and resolve on their own within a few days.

The other options do not accurately reflect common side effects associated with the Hepatitis B vaccine. While severe allergic reactions can occur, they are rare and do not happen in all recipients, making it an inaccurate assertion. Immediate relief from headaches and reduction in blood pressure are unrelated to the vaccine's expected outcomes or side effects and do not typically occur as a result of receiving the Hepatitis B vaccination. Thus, pain at the injection site remains the most relevant and representative potential side effect among the choices provided.