So much pain/ Stabbing pain like a knife throughout her body/ Achy all over; low grade fever but went up to 100.6 degrees; Chills; Couldn't walk, loss of balance; Headache; Neck pain; Tremors; Couldn't walk, loss of balance; so sick she was crying; More severe reactions; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A female patient received BNT162b2 (BNT162B2), as dose 4 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (DOSE 1, SINGLE), for COVID-19 immunization, reaction(s): "Couldn't walk, loss of balance", "Chills", "Headache", "Neck pain", "Pain", "low grade fever but went up to 100.6 degrees", "Tremors"; Bnt162b2 (DOSE 2, SINGLE), for COVID-19 immunization, reaction(s): "Couldn't walk, loss of balance", "Chills", "Headache", "Neck pain", "Pain", "low grade fever but went up to 100.6 degrees", "Tremors"; Bnt162b2 (DOSE 3, SINGLE), for COVID-19 immunization, reaction(s): "Couldn't walk, loss of balance", "Chills", "Headache", "Neck pain", "Pain", "low grade fever but went up to 100.6 degrees", "Tremors". The following information was reported: PAIN (non-serious), outcome "unknown", described as "So much pain/ Stabbing pain like a knife throughout her body/ Achy all over"; PYREXIA (non-serious), outcome "unknown", described as "low grade fever but went up to 100.6 degrees"; CHILLS (non-serious), outcome "unknown"; BALANCE DISORDER (non-serious), GAIT INABILITY (non-serious), outcome "unknown" and all described as "Couldn't walk, loss of balance"; HEADACHE (non-serious), outcome "unknown"; NECK PAIN (non-serious), outcome "unknown"; TREMOR (non-serious), outcome "unknown", described as "Tremors"; ILLNESS (non-serious), outcome "unknown", described as "so sick she was crying"; CONDITION AGGRAVATED (non-serious), outcome "unknown", described as "More severe reactions". Relevant laboratory tests and procedures are available in the appropriate section.  Additional information: Caller stated she got Pfizer Covid vaccine booster, latest vaccine Tuesday morning (unspecified date). Caller stated she was recommended to take this vaccine by a family member who was a doctor. Caller asked if those were the usual reactions. Caller stated she also had those reactions with the previous Pfizer Covid vaccines, but this time they were more severe. The caller stated she had so much pain, so sick she was crying. Had a low grade fever but went up to 100.6 degrees Fahrenheit Chills Tremors Stabbing pain like a knife throughout her body Couldn't walk, loss of balance Achy all over Headache Neck pain. Caller stated her husband had some of these bad reactions from the Pfizer Covid vaccines. Caller did not specify which reactions. Caller states her husband has not gotten any booster yet. Caller did go online to see if these effects were unusual. Caller stated she did not see information anywhere that showed any severity. Caller would like to speak to someone to find out. Caller stated she would talk to her physician to see if maybe her husband should take the Moderna vaccine next time instead of the Pfizer vaccine. She just wanted to find out if those effects were the usual reactions.  The information on the batch/lot number for [BNT162B2] has been requested and will be submitted if and when received.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202201264913 similar report from same reporter;