Can I take fever-reducing medicine if I have a fever on the third day after receiving a vaccination?

Generally, if a fever occurs on the third day after receiving a vaccination, antipyretic medication can be taken if the body temperature is high or discomfort is significant. However, if severe symptoms are present, medical attention should be sought first. If in doubt, it is recommended to consult a healthcare provider in advance. Detailed analysis is as follows:

If the fever on the third day exceeds 38.5℃, or if there is notable discomfort such as headache or muscle pain—even if the temperature does not reach this level—and no serious symptoms like difficulty breathing or severe vomiting are present, antipyretic medication may be taken according to the instructions. Taking medication under these circumstances can relieve discomfort without interfering with the vaccine's subsequent immune response, helping the body better get through the reaction period.

If fever on the third day is accompanied by persistent high fever (temperature remains above 39℃ despite taking antipyretics), chest tightness, widespread rash, altered consciousness, or other concurrent symptoms such as coughing or diarrhea, self-treatment with antipyretics alone is not recommended. These conditions may indicate an adverse reaction or coexisting illness, and prompt medical evaluation is necessary to identify the cause and prevent delays in treatment.

When taking antipyretics for fever following vaccination, strictly adhere to the recommended dosage and avoid repeated dosing. Increase fluid intake and ensure adequate rest during this time. Continuously monitor body temperature and overall condition, and contact healthcare professionals promptly if any abnormalities occur.