The tetanus shot is an important vaccination that protects against a serious bacterial infection. Like many vaccines, the tetanus shot can lead to reactions as the body builds protection. These responses are typically mild and indicate that the immune system is actively working.
Tiredness as a Common Response
Feeling tired after a tetanus shot is a common side effect. This tiredness is a sign that your immune system is actively responding to the vaccine’s components. This process of building immunity requires energy, similar to how the body reacts when fighting off a mild infection.
The fatigue experienced is a result of the systemic immune response. Your body mobilizes various cells and proteins to recognize and remember the vaccine’s components, preparing for future encounters with the actual tetanus bacteria. This heightened activity can lead to a general feeling of weariness. Most individuals report that this fatigue is mild to moderate and typically resolves within 24 to 48 hours, though some may experience it for a few days.
Other Expected Reactions
In addition to tiredness, individuals may experience other mild-to-moderate side effects after a tetanus shot. These reactions are temporary and indicate a normal immune response. They can be categorized into local reactions at the injection site and more widespread systemic reactions.
Local reactions are common and include soreness, redness, or swelling where the shot was administered. Pain at the injection site is frequent, affecting about two out of three adults receiving the Tdap vaccine. These localized symptoms usually appear within minutes or hours and typically subside within a few days.
Systemic reactions can also occur as the immune system works throughout the body. These may include a low-grade fever, headache, and body aches. Some individuals might also experience mild nausea. These broader symptoms, like fatigue, are generally mild and tend to resolve within one to two days.
When to Seek Medical Advice
While most reactions to a tetanus shot are mild and temporary, it is important to know when to seek medical attention. Certain symptoms could indicate a more serious reaction requiring prompt evaluation.
You should contact a healthcare provider if you experience severe pain, redness, or swelling at the injection site that worsens or prevents you from performing daily activities. A high fever over 102.2°F (39°C), or symptoms that persist beyond 48-72 hours, should also prompt a medical consultation.
Seek immediate emergency medical attention for signs of a severe allergic reaction, known as anaphylaxis. Symptoms can include hives, swelling of the face or throat, difficulty breathing, a rapid heartbeat, dizziness, or weakness. These reactions are rare but can be life-threatening and typically occur within minutes to a few hours after vaccination.