very tired; kind of sick; mildly nauseous; stomach/ intestinal pain and wasn't able to eat as much as usual; stomach/ intestinal pain and wasn't able to eat as much as usual; stomach/ intestinal pain and wasn't able to eat as much as usual; digestion feels diminished and I can't eat as much without feeling overstuffed; digestion feels diminished and I can't eat as much without feeling overstuffed; This is a spontaneous report from a contactable other health professional. A 66-year-old non-pregnant female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 MRNA VACCINE), dose 1 via an unspecified route of administration, administered in the left arm on 19Feb2021 at 09:30 (Batch/Lot Number: EN6200) as a single dose for COVID-19 immunisation. The patient did not have COVID prior to the vaccination. The patient did not receive any other vaccine within four weeks of the suspect vaccine.  Medical history included gastroparesis from an unknown date and unknown if ongoing, osteoporosis from an unknown date and unknown if ongoing, appendectomy on 05Jan2021, with no known allergies. The patient did not have COVID prior to the vaccination. Concomitant medications included denosumab (PROLIA) and dietary supplements; all taken for an unspecified indication, start and stop date were not reported.  The patient previously took probiotics for recover intestinal flora; start and stop date were not reported.  On 19Feb2021, the patient experienced very tired (non-serious), kind of sick (non-serious), mildly nauseous (non-serious), stomach/ intestinal pain and wasn't able to eat as much as usual (non-serious), digestion feels diminished and i can't eat as much without feeling overstuffed (non-serious); all of which did not receive any treatment. adverse event: The patient had an appendectomy on 05Jan2021. The patient took a lot of probiotics to recover her intestinal flora. The patient was recovered from the appendectomy before receiving the Pfizer vaccine. The patient also reported as having gastropareses which made it difficult to eat enough food to keep her weight on. The patient stated she was 5'7" 100lbs. Right after the vaccination, the patient felt very tired and kind of sick. The sick feeling went away in a couple of days. The patient also felt mildly nauseous with some stomach/ intestinal pain and could not eat as much as usual (which was not enough anyway). The nausea was continuous except for a few sporadic days when she felt a little better. The patient at the time of the report weighed 98.5 lbs. The patient generally was feeling less nausea and the pain was mostly gone as time went by, but her digestion felt diminished and she could not eat as much without feeling overstuffed. The patient thought she felt good enough to get the second dose, however, she was very concerned about her lack of digestive strength. The patient was due to have the second dose on 17Mar2021. The patient underwent lab tests and procedures which included weight: 98.5 lbs on an unspecified date.   The clinical outcome of the event, kind of sick, was recovered on an unspecified date. The clinical outcome of the events: Nausea, Abdominal Pain Upper, Gastrointestinal Pain was recovering. The clinical outcome of the event, Fatigue, Hypophagia, Dyspepsia, Feeling Abnormal  was not recovered.