Tiredness; Loss of appetite; lack of energy; Chills; Fever; Soreness at the injection site; Warmness at injection site; difficult to lift his arm; This is a spontaneous report from a contactable consumer (parent). A 12-year-old male patient received (PFIZER-BIONTECH COVID-19 VACCINE, formulation: solution for injection, Batch/Lot number: EV00191) via an unspecified route of administration in left arm on 22May2021 at 11:00 (age at vaccination 12-year-old) as dose number unknown, single for Covid-19 immunization. The patient's medical history was none. The patient's concomitant medications were none. The patient previously took Flu vaccine, 2 years before, onset Age was about 10 years and experienced flu symptoms. Patient was healthy, no allergies and no medical history. Not even regular vitamins. Patient did not receive any other vaccines on same date of the pfizer suspect. Patient did not receive any other vaccines within 4 weeks prior to covid vaccine. Patient's mother was a bit concerned. He was doing great and then on 23May2021, Sunday onwards he had chills. Then he had a temperature of 100 and she gave him plain acetaminophen and Sunday onward 6 or 7 hours onward he kept getting chills. On 23May 2021, for six to seven hours, he had chills. There have been temperatures of 90 and she has to give him a blanket or heater. It was more or less the same today 26May2021 Attempted to clarify that the caller stated the intensity was a little less. Caller confirmed. She thought it was a normal reaction and waited patiently for 3 days. She was not allowing the temperature to go up as soon as he gets chilled and breaks into fever, she checked his temperature and it was always less than 100 like 99.9 or 99.7 Fahrenheit, axillary. Then he broke into a sweat and feels a little better. He also had tiredness and loss of appetite on 24May2021. She also reported that on 22May2021, his arm was sore and difficult to lift and then it disappeared in one or two days. He took the vaccine on 22May2021 in the morning and then by Monday symptoms were gone, the soreness, and warmness at injection site. Patient experienced tiredness on Monday 24May2021 in the morning after fever, the lack of energy and tiredness started. On 24May2021 patient experienced loss of appetite. His breakfast, lunch or dinner reduced to one fourth. On 22May2021 in the morning started in the evening, around 6 or 7 o'clock, patient experienced soreness at the injection site. On 22May2021 in evening, patient experienced warmness at injection site. The time range for adverse events was 3 to 5 days. 3 days of fever no one gives her answers. Pediatrician says wait and after 4 or 5 days they look into it. Adverse events did not result into emergency room visit and physician office visit. Treatment received for chills was gave acetaminophen every 6 to 7 hours. Treatment received for fever was Tylenol every 6 to 7 hours. Treatment received for tiredness and lack of energy was keeping him hydrated and his appetite was quite less and she was giving him lemon juice keeping fluids. Treatment received for event warmness and soreness at injection site was gave him ice and it helped a lot localized. Patient did not receive any treatment for event loss of appetite. The patient underwent lab tests and procedures which included fever was 99.9 and 99.7 Fahrenheit on 23May2021. The outcome of event chills was unknown. the outcome of event pyrexia, tiredness, loss of appetite and lack of energy was not recovered. the outcome of event soreness and warmness at the injection site and difficult to lift his arm was recovered on 24May2021.  No follow-up attempts are possible. No further information is expected.