Pt received the first of the two-series COVID vaccination at 1512. Once in observation area, pt became unresponsive shortly after sitting down. This provider was called over by staff to pt, which was noted to have become unresponsive while sitting in the chair. Pt remained in the chair, did not fall or injure self. Upon arrival to patient, he was noted to have severe diaphoresis, prominent pallor, with shallow, slow breathing, no cyanosis noted. His head initially fell back and head was aligned/adjusted to maintain an open airway. This provider was speaking to the pt and performed a sternal rub to elicit a response, pt remained unresponsive and with eyes closed. Pt remained in this state for approximately 10 seconds. Pt noted to suddenly have some muscular rigidity to arms and torso and in order to prevent injury upon possible onset of seizure activity, pt was lowered to the floor by this provider and RN . Once on the ground the pt was relaxed and opened his eyes. Pt was immediately verbally responsive and asked if he passed out. Pt was able to sit up and was assisted into the wheelchair. Pt moved to treatment area where vitals and blood glucose were obtained. (@1525 BG- 104 mg/dL, VS BP 116/72, HR bradycardic @51 bpm, O2 sat 95%).  Patient responses/speech was clear and pt was oriented to self, place, time and situation. Pt stated that he felt nauseated upon sitting in the observation area and admitted that he only had a coffee today, nothing to eat all day and attributed this as the cause of his reaction. Pt verbalized that he would not respond to the hospital with the paramedics and was encouraged to at least call someone to take him to the hospital.  This provider spoke with the patient?s mother and explained the events. The patient?s mother stated that the patient had febrile seizures when approximately 4 years old, associated with asthma exacerbations; but pt was evaluated with a neurologist and there were no abnormal findings. Pt admitted that he has a similar syncopal episode after washing a laceration and seeing his finger bleeding. Pt states this was a few years ago and witnessed by his father that told the patient he initially fainted and then became momentarily rigid before responding appropriately (similar to today?s events).   Ambulance - arrival @1536 report given and pt stated he was feeling better and declined further evaluation in truck and also declined transport to ED ( departed at 1545). Pt?s overall condition, appearance, including color was much improved. Pt denied any allergies or medication history. Past medical hx of febrile seizures at approximately age three and four, childhood asthma and one syncopal episode as an adult. Pt girlfriend  arrival and she agreed to drive patient from the vaccine clinic.  Pt and girlfriend were both provided with an explanation of the many concerning causes of syncope and the necessity for further evaluation in the Emergency department to rule out any underlying conditions. Both patient and girlfriend verbalized understanding and although they still declined to respond to ED directly from the clinic, both did agree to respond to ED if any changes in mental status occurred.  Pt lives alone, but agreed to stay with parents and family in order to have others watch him for any changes.  Pt was advised to followup with PCP and made aware that an  provider would contact him tomorrow to check on his status, understanding verbalized and agreed with plan of care.  Pt in no acute distress, awake, alert and oriented. Color within normal limits for  and departed facility with girlfriend at 15:56, steady gait noted.  Patient?s appointment for second dose was cancelled and will need to obtain clearance prior to second vaccine dose.