Client reported feeling dizzy immediately after administration of the COVID vaccine Janssen. Noted the client was rubbing his forehead and eyes. The client's eyes were closed. When the client opened his eyes. Noted the client's eyes appeared red.  Noted that this redness was not present prior to receiving the vaccine. The client was deliberately shaking his hands bilaterally and squeezing his hands into fists. Asked the client what his current symptoms were and he did not verbally respond. Repeated the question. A few seconds later the client stated he felt "dizzy and weird." The client stated that he felt something in his right leg, but RN was unable to discern what the client said. RN noted shaking of the client's right leg. The client stood up with the assistance of his cane and support of the arm of the anti-gravity chair and transferred into the anti-gravity chair. The client appeared unsteady on his feet to RN. The anti-gravity chair was reclined. The client was verbally unresponsive for a few seconds. RN noted the client's head leaned against the anti-gravity chair and the client's eyes were closed. The client then opened his eyes. The client was alert and oriented to person, place, and time. The client reported feeling "dizzy, weak, and sleepy, like when you have surgery." The client denied any chest pain or shortness of breath. Vitals obtained at 1:39PM were as follows: BP 147/94 and HR 84. The client stated he felt thirsty, RN offered the client water. The client did not drink the water. At 1:43PM the client reported "my tongue feels like when you take medicine." The client subsequently clarified that his tongue felt "swollen." RN assessed the client's tongue and did not note any swelling and noted the client's tongue was pink. The client has a history of seizures and takes Dilantin. The client states he took his Dilantin this morning as prescribed. The client stated his current status feels different than his seizures. The client states that when he has a seizure he "shakes a lot and then I can't talk." Vitals obtained at 1:46PM were as follows: BP 134/90 and HR 90. The client stated that his tongue still felt "swollen." The client stated that he took the trolley to the vaccination site and does not have anyone who could come and pick him up. The client stated his throat felt "itchy." Offered the client Diphenhydramine IM. The client reported a history of an allergy to Keppra where he developed a rash. The client denied any history of anaphylaxis. Oxygenation status obtained via pulse oximeter at 1:52PM was 97%. The client stated that he would like to receive Diphenhydramine IM. RN educated the client regarding Diphenhydramine including risk of drowsiness. The client voiced understanding of this education and gave verbal consent to receive Diphenhydramine IM. The client stated his dizziness was improving and that he still felt tired at 1:52PM. RN administered 50mg/1ml Diphenhydramine (Lot# 020020 exp 02/2022) in the right deltoid muscle at 1:53PM. The client was verbally non-responsive for a several seconds after receiving the Diphenhydramine. RN noted shaking of the client's right leg. The client's head was heavy on the anti-gravity chair. The client then attempted to sit up quickly. RNs reassured the client of the situation and the client relaxed in the chair. RN activated EMS at 1:55PM. The client stated "I can't breathe". RN noted the client clutching his chest. The client reported repeated difficulty with respirations. Prepared to administer Ephinephrine by removing the cap and safety release. RN prepared to administer the Epinephrine when the client moved quickly and stated "no." RN did not administer Ephinephrine. RN educated the client regarding Ephinephrine and continued to question the client regarding his respiratory symptoms. The client appeared more alert to RN and began to respond to questions more clearly. RN noted no pallor or use of accessory muscles. The client stated that his breathing was improving. Vitals obtained at 2:00PM were as follows: BP 146/88 and HR 84. The client denied any persistent weakness. The client appeared disoriented to RN. The client stated that his right arm hurt. RN explained that was likely related to the Diphenhydramine administered IM into the right deltoid. The client asked RN, "I received another injection?" RNs educated the client regarding the administration of Diphenhydramine IM. The client voiced understanding of this education. EMS assumed care at approximately 2:03 PM. The client was transported to ER 2:09PM.