Client received her 2nd dose of the COVID19 Pfizer vaccine (Lot# FF8839) at 13:36. The client was accommodated by her minor son while her husband and other children waited in the car.  After receiving her injection, the client went to the observation area to sit for 30 minutes.  At 13:55, the client alerted Lead RN and EMT she was not feeling well and started crying.  The client was Spanish speaking and Ancillary staff was utilized to translate for the client.  Client stated she felt tightness in her throat, her heart was racing, and she had throbbing pain in the back of her head.  Lead RN and EMT also observed the client was trembling, diaphoretic, and appeared to have anxiety.  Client stated she was not experiencing shortness of breath, difficulty breathing, or chest pain.  Lead RN and EMT transferred the client into the anti-gravity chair.  Lead RN grabbed 2 ice packs, placing one on the back of the client?s neck and used the other to cool the client?s face and forehead.  At 13:57 EMT put a pulse oximeter on the client?s finger (HR: 152, SPO2: 99%) and left it remaining on her finger for monitoring purposes.  Lead RN asked the client to take deep breaths and try to relax.  Lead RN observed client was alert and oriented to person, time, place, and situation.  Lead RN also asked the client if she has any underlying health conditions or allergies.  Client stated she has high blood pressure, hypothyroidism, and depression.  Client stated she takes the following medications: Lisinopril, Levothyroxine, and Buspirone.  She takes her medications at night and is medication compliant.  Client is allergic to Aleve and previously experienced an anaphylactic reaction.  Client stated she did not experience any immediate side effects from the 1st dose of the COVID19 Pfizer vaccine.  But, several days later she began experiencing severe headaches that have not subsided and she has not sought medical attention.  She also stated she had a headache before she came to get the 2nd dose of the vaccine and was feeling nauseous earlier.  Client stated she took 2 Tylenol Sinus pills for her headache before coming in.  At 14:00 Lead RN observed the client?s heart rate on the pulse oximeter was decreasing (HR: 126, SPO2: 99%).  Lead RN observed the client was calmer and no longer crying.  Client confirmed she was still not experiencing any shortness of breath, difficulty, breathing, or chest pain.  She also stated her throat was feeling OK, but she was experiencing a severe headache.  Client stated she last ate at 10:00.  Client was offered a granola bar, water, and juice, which she accepted.  Client drank some of the water and juice and ate some of the granola bar.  At 14:06 EMT took the client?s vitals (BP:  150/122, HR:132, SPO2: 99%).  Client began to feel agitated and started crying again, stating ?my head hurts.?  Client stated her blood pressure is not usually that high.  At 14:10, due to the client?s tachycardia, headache, and noted diastolic blood pressure in the hypertensive crisis range, Lead RN called 911 for paramedic assistance.  Client agitation and anxiety continued to escalate.  At 14:14 client communicated she was having trouble breathing and started to hold her throat.  Lead RN had one hand on the client?s shoulder, guiding her to take breaths.  Client then began hunching over, desperately screaming, and then started gasping for air.  She said her throat was closing and her hands were feeling numb.  At 14:15 Lead RN authorized EMT to administer 0.3 mg IM epinephrine pen injection in the client?s left anterolateral thigh.  Immediately afterward, the client leaned back in the chair, stopped gasping for air, calmed down, and stopped grabbing her throat.  Lead RN observed the client?s chest was moving up and down bilaterally.  EMT utilized her stethoscope to check the client?s lungs, communicating they were clear.  At 14:16, Lead RN called 911 a second time to communicate the client?s change in condition.  At 14:17, the Fire Department Paramedics arrived at the building and at 14:18 they arrived in the observation area.  After assessment, paramedics concluded the client was having an anxiety and panic attack.  At 14:24, they put her on a sit-up gurney and transported her outside for further assessment.  At 14:31 the paramedics escorted the client to her vehicle and the client left with her husband and children.  At 14:34, paramedics left the facility.