Tetanus shot side effects: what to expect

Soreness, warmth, redness, or a small area of swelling around the injection site reflects a local immune response. The arm may feel stiff when you lift it. Tiredness, headache, muscle aches, or a mild fever can also occur as the body responds to the vaccine. These effects do not mean that you have tetanus, and they do not make the vaccine infection contagious.

A tetanus-containing injection may be given on its own or combined with protection against other infections, so the exact product and your previous vaccination history can affect what your clinician advises.

Rest if you feel tired, drink fluids, and move the arm gently to reduce stiffness. A cool, clean cloth on the injection area may ease discomfort. If you normally can take them, ask a pharmacist or clinician whether a pain or fever medicine is suitable for you; follow the label directions and mention pregnancy, allergies, or other medicines. Avoid rubbing the injection site or taking extra doses simply to prevent a reaction.

Contact the vaccination clinic if local swelling becomes increasingly painful, spreads substantially, or does not start settling, or if fever or other symptoms are troubling you. Keep the vaccine record and note when the symptoms began.

Call emergency services immediately for trouble breathing, swelling of the lips, tongue, face, or throat, widespread hives, fainting, severe dizziness, or sudden weakness after the injection. These may signal a serious allergic reaction. Seek prompt medical advice for a very high or persistent fever, confusion, a seizure, severe headache, or symptoms that rapidly worsen.

If you are unsure whether a symptom is vaccine-related, tell the clinician when the shot was given, which symptoms appeared, and whether they are getting better or worse.

Ask which tetanus-containing vaccine you received, which reactions are expected for that product, and what you can safely use for pain or fever. If you have had a previous vaccine reaction, ask whether it changes your vaccination plan and which warning signs should prompt urgent help.