What action is not a standard response when a patient experiences syncope after vaccination?

Administering oxygen is not considered a standard response after a patient experiences syncope due to vaccination. Syncope, or fainting, often occurs due to a temporary drop in blood flow to the brain, which is generally managed through physical positioning and monitoring rather than by administering oxygen. Elevating the patient's legs is a common practice to help increase blood flow to the brain and facilitate recovery. Monitoring vital signs is crucial to ensure the patient's stability and to assess any further complications. Calling for emergency services is warranted if the patient does not regain consciousness or shows other concerning symptoms. In the absence of evidence indicating hypoxia or respiratory distress following syncope, oxygen administration is not a routine response.