if she was possibly having an allergic reaction to the vaccine because of the slow swelling in her stomach; she was being paranoid; the upper part of her stomach felt like it was expanding/she had a slow swelling feeling in her stomach after she had her second covid-19 vaccine; she threw up a few times, and then the vomiting; she has a tin taste in her mouth still; she still felt a little nauseous today; Stomach pain; she felt like her inside was going to explode; This is a Spontaneous report received from a 61-year-old contactable female. This female patient reported for herself. A 61-years-old female patient received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, formulation: solution for injection, Batch/lot number: ER8733) via unknown rote of administration in right arm on 01Apr2021 at 14:40 (at the age of 61 years old) as DOSE 2, SINGLE for COVID-19 immunisation and also received acetylsalicylic acid (ALKA-SELTZER) via unknown route of administration on 01Apr2021 for an unknown indication. The patient medical history included allergy to Penicillin for approximately 30 to 40 years and gastric bypass 20 years ago, she was very much overweight, and had heartburn and indigestion issues. The concomitant medications were not reported. Historical vaccine included first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, formulation: solution for injection, Batch/lot number: EN6199) via unknown rote of administration in right arm on 11Mar2021 as DOSE 1, SINGLE for COVID-19 immunisation and had no problems. It was reported that patient had the second dose of the vaccine yesterday, on 01Apr2021, within 30 to 45 minutes, from leaving the convention center where she got her second COVID-19 Vaccine, she and her husband went to a restaurant to eat. She said she had 1 bite of soup, and 1 bite of salad, and then the upper part of her stomach felt like it was expanding and bloating. She said she felt she was going to throw up, and her inside was going to explode. She said she had her husband pack up her food, and they went home. She said when she got home, she threw up a few times, and then the vomiting subsided. She said her husband suggested she take an Alka Seltzer to settle her stomach. She said she took 1 Alka Seltzer with a 1/2 cup water, and threw up, again. She said she didn't throw up anymore after that and felt fine today (02Apr2021).  She stated she was allergic to Penicillin and thought maybe she was having an allergic reaction to the COVID-19 Vaccine. She clarified with Penicillin her neck swelled up. She said she had a slow swelling feeling after she had the COVID-19 Vaccine, but the slow swelling feeling was in a different spot than her neck. She clarified the slow swelling feeling as in her stomach, describing it as stomach bloating and pain. she also had a tin taste in her mouth right away after she received her second COVID-19 Vaccine. She said the tin taste was no big deal. She clarified she noticed after drinking water this morning that she still had a slight tin taste in her mouth. She said there was another person at the COVID-19 Vaccination facility (at the same time as her) that had told her he had the same experience with the tin taste after getting the COVID-19 Vaccine. She said clarified the person was someone her husband knew. She said she didn't really know anything about that person except he was a male around her age. She said clarified he mentioned a "tinny" taste after getting the COVID-19 Vaccine. It was reported she took only 1 Alka Seltzer in a 1/2 cup of water. She said immediately upon taking a swallow of the Alka Seltzer, her stomach started expanding, and the Alka Seltzer made her feel bad. She said her stomach felt all closed up, and the Alka Seltzer couldn't go anywhere. She said she immediately threw up again. She said she didn't throw up again after that. She stated she had taken the last Alka Seltzer and had thrown away any product packaging. It was reported the stomach bloating and pain went away 1 to 1-1/2 hours after she took the Alka Seltzer. Reported she still felt a little nauseous today and was being cautious. She said she had coffee this morning, and the coffee didn't bother her. No further details provided. She stated she was allergic to Penicillin and thought maybe she was having an allergic reaction to the COVID-19 Vaccine. She clarified with Penicillin her neck swelled up. She said she had a slow swelling feeling after she had the COVID-19 Vaccine, but the slow swelling feeling was in a different spot than her neck. She clarified the slow swelling feeling as in her stomach, describing it as stomach bloating and pain. She said the stomach bloating and pain went away 1 to 1-1/2 hours after she took Alka Seltzer. Reported she also had a tin taste in her mouth right away after she received her second COVID-19 Vaccine. She said the tin taste was no big deal. She said she noticed after drinking water this morning (02Apr2021) that she still had a slight tin taste in her mouth. The patient did not visit emergency room and Physician Office due to the events. No other vaccines Prior Vaccinations (within 4 weeks). The outcome of the events she was being paranoid and if she was possibly having an allergic reaction to the vaccine because of the slow swelling in her stomach were unknown, she has a tin taste in her mouth still and she still felt a little nauseous today were recovering and other was recovered on 01Apr2021.  No follow-up attempts were needed. No further information was expected.