Anaphylaxis; Allergic reaction; Wheezing; My brain is not working, I don't feel so great; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A patient (no qualifiers provided) received BNT162b2 (BNT162B2), on 29Apr2022 as dose 4 (booster), single (Lot number: FK8729) for covid-19 immunisation. The patient's relevant medical history included: "Immune system problem" (unspecified if ongoing), notes: Immune system problem. The patient's concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (Primary Immunization series complete; Unknown manufacturer), for COVID-19 immunization; Covid-19 vaccine (Dose: 03), for COVID-19 immunization, reaction(s): "I had a problem just a hoarseness and I was sick like 2 weeks"; Covid-19 vaccine (Dose: 03), for Covid-19 immunization, reaction(s): "Sick". The following information was reported: HYPERSENSITIVITY (hospitalization) with onset Apr2022, outcome "unknown", described as "Allergic reaction"; ANAPHYLACTIC REACTION (hospitalization, medically significant) with onset Apr2022, outcome "unknown", described as "Anaphylaxis"; CEREBRAL DISORDER (hospitalization) with onset Apr2022, outcome "unknown", described as "My brain is not working, I don't feel so great"; WHEEZING (hospitalization) with onset Apr2022, outcome "unknown".  Additional Context: Concern, consumer stated, "I got my 4th COVID Booster (Pfizer COVID-19 Vaccine) yesterday and I got Pfizer obviously. I had an adverse effect and I went to the Hospital after coming home but I had an allergic reaction to it. I literally had to 'appease' (word not clarified hence not captured as an event) and then they had to keep me there for a while and everything else, so the 3rd Booster I had a problem with too but it was just a hoarseness and I was sick like 2 weeks from it but this one is the first time that I actually had an anaphylaxis and that is not something you usually get. I have immune system problem (history). This is the first time that I have ever had the wheezing. If that is the well to that point or where I had to go to the Hospital or is that basic problem." Vaccine name: Pfizer COVID-19 Vaccine Consumer was informed about the Role of Pfizer Drug Safety. Consumer was informed about Pfizer Medical Information Department. In response file safety report, consumer stated, "My brain is not working, all I could do is just call and say what happened yesterday but the reaction is still, I have to have them for few days now. In order to make sure I don't have any more. You can just document it and I am just going to kind of hang up now. I don't feel so great." Vaccine LOT#FK8729 (captured in the tab) When probed for vaccine Expiration date, consumer stated, "I am looking at the expiration and I can't make sure as I don't read it. It says and it looks like 01 or 07/0109 and then it says 22, I think." (Consumer was further not sure about expiration date hence not captured in the tab) As consumer was not willing to proceed the call. Hence further probing could not be done. Limited information available over the call and appropriate response could not be provided. QR comment: Reporter type was not available over the call, hence reporter type was captured as consumer or non-healthcare professional by default.  No follow-up attempts are possible. No further information is expected.