she felt cold, then hot; she felt tired and weak; feel hot; she felt tired and weak/weakness; she felt cold/cold sensation; chills; headache; have a temperature of like 99 to 99.1/temperature went to 99.1; This is a spontaneous report from a contactable physician (patient). A 41-year-old female patient received first dose bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Batch/lot number: EK5730, Expiry Date: Mar2021), intramuscular in left deltoid on 16Dec2020 around 2:00 or 2:30 in the afternoon at single dose for COVID-19 immunisation. Medical history included none.  Concomitant medications included colecalciferol (VITAMIN D), ascorbic acid, ergocalciferol, nicotinamide, retinol, riboflavin, thiamine hydrochloride (VITAMINS [ASCORBIC ACID;ERGOCALCIFEROL;NICOTINAMIDE;RETINOL;RIBOFLAVIN;THIAMINE HYDROCHLORIDE]). The patient previously took flu shot on 16Oct2020 at age of 41-year-old for immunization. Caller asking if is possible to see side effects days later after getting the vaccine. Caller report her symptoms which the caller reports started 4-5 days after receiving the vaccine. Symptoms included were chills, weakness, headache and temp. Caller on the line a doctor, MD, calling about the COVID Vaccine. She mentioned she got the shot last week, 16Dec2020. Almost like the fourth day after getting the vaccine, that Sunday (20Dec2020), she started to experience chills and have a temperature of like 99 to 99.1. She did not get the vaccine through her doctor. She got the vaccine at the hospital she works at. She explained on Sunday (20Dec2020) night, she felt cold. She had to use a couple of blankets and wear a sweatshirt which was not usual for her. On Monday 21Dec2020, she felt tired and weak. That afternoon and evening she felt chills as well. It was like all of a sudden she had a cold sensation. She commented her normal temperature always runs like 97.6 to 98. Her temperature went to 99.1, something like that. However, she confirmed it did not go above that. She would feel hot at times and chilly at times. She also mentioned she experienced headaches. Yesterday (22Dec2020) morning she felt better. Last evening it was not that bad. She mentioned with chills she felt cold, then hot. She checked her temperature and it was 98.8 something like that. Just a little higher than her normal. Outcome of chills: Stated this morning she was fine, but in the evening it is worse. Felt weak: She mentioned there was time where she was fixing lunch and after it was cooked she felt weak and like she had to sit right away. Headache: Had an episode Sunday (20Dec2020) night and it happened again yesterday. The headaches for short periods. Caller confirmed this was the first dose received of the COVID vaccine. She confirmed she does not know if the chills, feeling weak, headache, or temperature is related to the COVID vaccine. She mentioned she has no other symptoms like cough. She also added she was tested for COVID and it was negative. She had the test done on 22Dec2020. At end of call, caller questioned, it was asked if it is possible to have side effects days later after getting the COVID vaccine and it be related to the vaccine. She stated she's read it's common for it to occur like two days after, but not this long afterwards. Vaccination Facility Type was Hospital. Vaccine Administered at a Military Facility was No. Additional Vaccines Administered the Same date of the Pfizer Suspect was None. No AE(s) require a visit to the Emergency Room or Physician Office. The outcome of the event weakness was not recovered. The outcome of the event have a temperature of like 99 to 99.1/ temperature went to 99.1 was recovering. The outcome of other events was unknown.