lightheaded, dizzy; weak; couldn't stand up; couldn't function or eat/ couldn't eat for 2/12 days; couldn't walk/couldn't even walk to the door; felt like I was dying; sick/in bed deathly ill for 3 days; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 93-year-old female patient received BNT162b2 (BNT162B2), in 2021 as dose number unknown (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "hard of hearing" (unspecified if ongoing); "she only has 1 kidney" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (Primary Immunization series complete; MANUFACTURER UNKNOWN), for Covid-19 Immunization. The following information was reported: DIZZINESS (non-serious), outcome "unknown", described as "lightheaded, dizzy"; ASTHENIA (non-serious), outcome "unknown", described as "weak"; DYSSTASIA (non-serious), outcome "unknown", described as "couldn't stand up"; EATING DISORDER (non-serious), outcome "unknown", described as "couldn't function or eat/ couldn't eat for 2/12 days"; GAIT DISTURBANCE (non-serious), outcome "unknown", described as "couldn't walk/couldn't even walk to the door"; ANXIETY (non-serious), outcome "unknown", described as "felt like I was dying"; ILLNESS (non-serious), outcome "unknown", described as "sick/in bed deathly ill for 3 days". The events "lightheaded, dizzy", "weak", "couldn't stand up", "couldn't function or eat/ couldn't eat for 2/12 days", "couldn't walk/couldn't even walk to the door", "felt like i was dying" and "sick/in bed deathly ill for 3 days" required physician office visit.  Additional information: Reporter stated that she received her Pfizer COVID-19 1st booster vaccine in Nov or Dec2021. Caller stated that she had a very bad reaction after receiving her Pfizer COVID-19 booster vaccine. Caller stated she felt lightheaded, dizzy, weak, couldn't stand up, couldn't function or eat, couldn't walk, and felt like she was dying. Caller stated that after receiving her booster vaccine she laid on hall floor, and couldn't eat for 2/12 days. Caller stated that she only has 1 kidney and managed to drink. Caller stated she was in bed for 3 days and couldn't let ambulance driver in the door after calling 911. Caller stated her doctor is recommending that she get the 2nd Pfizer Covid19 booster dose, but she is worried because she lives alone and is afraid she won't be able to get to the door again to let ambulance staff in to help her. Caller enquired if there was pediatric Pfizer COVID-19 booster vaccine that she could take instead of the adult formulation. Caller enquired if the pediatric booster dose 1/2 the potency of the adult dose so she won't have as many side effects if she took it. Confirmed Pfizer Covid19 2nd booster vaccine. Spoke from PI Section 3: DOSAGE FORMS AND STRENGTHS: Each dose of the Pfizer-BioNTech COVID-19 Vaccine supplied in vials with gray caps and labels with gray borders is 0.3 mL for individuals 12 years of age and older. Other Conditions: Not Provided. Investigations: Not Provided. Other Products: Not Provided. Caller stated she was hard of hearing and needs question repeated. Caller stated she was calling about the 2nd vaccine and the booster. She stated especially the booster. Caller stated she was so sick she couldn't even walk to the door to let the people in. She stated she couldn't eat anything and was in bed deathly ill for 3 days. She is wondering because she is afraid to get a another booster because she stated she can't be sick like that again. Caller wondered if the pediatric dose is like a watered down version of the adult dose. She stated like half of the adult dose or something like that. She stated she had such a terrible reaction she is scared to get another booster. Caller stated the trouble is her primary care physician retired and she doesn't have another doctor yet. She stated the doctors she had seen she had been unhappy with.   The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.