Tachycardia; Lost 14 pounds; Ulcerative colitis flare up; Throat and glands swollen; Throat and glands swollen; vomiting a lot and couldnt hold food and water down; Diarrhea; This is a spontaneous report received from a contactable consumer (reporting on herself). A 18-years-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Lot Number: EW0150; Expiration Date: 31Jul2021) via an unspecified route of administration in Arm Left on 07Apr2021 13:30, as 1st dose, single dose and BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Lot Number: EW0171; Expiration Date: was not reported ) via an unspecified route of administration in Arm Left on 28Apr2021 12:30, as 2nd dose, single dose for COVID-19 immunization. Medical history included colitis ulcerative from 2015 and ongoing. Additional Information for Other Conditions: states was in remission for 6 years prior to her second dose of the vaccine. The patient's concomitant medications were not reported. It was reported that she had a pretty severe reaction to her second dose of BNT162B2. States she has been in the hospital for 5 days last week and has now been in the hospital for 4 days this week because of side effects from vaccine that she received on 28Apr2021 which was her second dose. She thought the side effects would go away after the first hospitalization but was readmitted. First admitted to the hospital on 01May2021 for severe reaction to the shot for 5 days then was sent home because they thought the side effects would go away but the side effects have still been heavy. She was admitted again on Friday (14May2021) to the hospital from the side effects that are continuing. States she had lost 14 pounds from the time she was home from her first visit to the hospital. Patient vomiting a lot and couldnt hold food and water down: States that right after she got the second shot a couple of hours later she vomited a lot and couldn't hold food or water down which started 28Apr2021 and that she hasn't thrown up since Friday 14May2021, but has improved. She was starting to recover from it, it was just starting to get better. The really bad diarrhea started on the 28Apr2021 and was ongoing. The doctor thinks the second dose of the vaccine caused an ulcerative colitis flare up. She noticed the tachycardia on 29Apr2021. States her resting heart rate before the vaccine was 55 on average and now her resting rate was 105-115, and when she gets up to walk around it was 140-160. States that this was what was preventing her to be able to leave the hospital now. Tachycardia was the reason for admission for the first hospitalization. she was at urgent care she was tachycardic and her throat and glands were all swollen and they thought she needed to be admitted to the hospital. Swollen glands recovered last week, either 12 or 13May2021 and was completely recovered from that. Clarifies throat and swollen glands recovered 13May2021. Her dates of admission were 01May2021- 04May2021 for tachycardia. States she was currently at hospital and was admitted 14May2021 and was still there today for tachycardia and weight loss. States the tachycardia warranted both hospital admissions but the weight loss also contributed to the second admission as well. States her current weight was 116 after losing 14 pounds. She was weighed on the 4th when discharged from her first hospital admission and she weighed 130 pounds or 59 kilograms then had a follow up appointment with her cardiologist on the 14th for tachycardia and was weighed then and was 116 pounds at that time. They then sent her to the emergency room right after that follow up appointment to be admitted. States she hasn't been weighed again during this hospital admission so she thinks her weight was the same. She coughed and said sorry something got stuck in her throat, then continued her conversation. Ulcerative Colitis flare up- states she was unsure of when it transitioned from diarrhea to this flare up of ulcerative colitis. States she has just starting getting steroids and they increased her normal medications for her condition and was starting to improve. States she has a picture of her vaccine card and the events started after her 2nd dose. They did a procedure to confirm it was flare up at around 15:00 on 17May2021, performed a sigmoidoscopy and just found her left colon and rectum were inflamed as results which was similar to the ulcerative colitis flare up. The patient underwent lab tests and procedures which included heart rate: 55, heart rate: 105-115, heart rate: 140-160 on an unspecified date, sigmoidoscopy: found her left colon and rectum were inflamed as r on 17May2021. The outcome of the ulcerative colitis flare up was recovering, for event tachycardia, diarrhea and on 29Apr2021 with outcome of not recovered , lost 14 pounds was not recovered, and for vomiting a lot and couldnt hold food and water down was unknown and for events throat and glands swollen was recovered on 13May2021.