This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the patient.  A 75-year-old female patient received BNT162b2 (BNT162B2), on 09Nov2021 as dose 3 (booster), single (Lot number: FF8841) at the age of 75 years, in left arm for covid-19 immunization. The patient's relevant medical history included: "Asthma" (unspecified if ongoing), notes: She has had asthma for probably 10 years.; "Acid reflux" (unspecified if ongoing), notes: The acid reflux and asthma together enhances the breathing problems from the acid coming up her esophagus.; "GERD" (unspecified if ongoing); "breathing problems" (unspecified if ongoing), notes: The acid reflux and asthma together enhances the breathing problems from the acid coming up her esophagus. Concomitant medication(s) included: PANTOPRAZOLE taken for gastroesophageal reflux disease; TUMS [CALCIUM CARBONATE]; ROLAIDS [CALCIUM CARBONATE;MAGNESIUM HYDROXIDE]; NEXIUM [ESOMEPRAZOLE MAGNESIUM]. Vaccination history included: BNT162b2 (First dose, Lot Number: EN6198, Route, Anatomical Location: Left upper arm), administration date: 25Feb2021, when the patient was 74-year-old, for COVID-19 Immunization, reaction(s): "GERD and acid reflux has disappeared after her COVID-19 vaccines", "has GERD and acid reflux and this disappeared 2 days after the first shot up to a couple days before her second shot"; BNT162b2 (Second dose, Lot Number: EN6206 or EN6266, Route, Anatomical Location: Left upper arm), administration date: 18Mar2021, when the patient was 74-year-old, for COVID-19 Immunization, reaction(s): "GERD and acid reflux has disappeared after her COVID-19 vaccines", "has GERD and acid reflux and this disappeared 2 days after the first shot up to a couple days before her second shot". The following information was reported: THERAPEUTIC RESPONSE UNEXPECTED (non-serious) with onset 09Nov2021, outcome "recovered" (13Nov2021), described as "GERD and acid reflux has disappeared after her COVID-19 vaccines".  Additional information: As per agent: Caller reported a positive reaction to the Pfizer COVID-19 Vaccine. She mentioned that her gastric reflux was gone away. Caller would like to know if there was any information on what was in the vaccine that can cause that acid production to go down. Caller stated that she has had severe acid reflux. However, after getting the Pfizer-BioNTech COVID-19 Vaccine it went away for a time. Every time she got the vaccine or the booster it disappeared 2-4 days after. Was there something in the vaccine that caused that? If there was something, it should be separated to be used in people with stomach problems. Patient have had it four times and four times her acid reflux had improved. It definitely had something. Patient took third dose of BNT162B2 in left upper arm, indication: to protect herself and family from COVID. She was unsuccessfully taking Pantoprazole at the time of her first COVID-19 Vaccine. This worked best of the medications she tried. Worked in the beginning and then stopped working. She had GERD and acid reflux and that disappeared 2 days after the first shot up to a couple days before her second shot and then 2 days after her second shot this went away. She reported the same thing happened after her booster shot as well where the GERD and acid reflux came back before her booster shot and then went away again after. Caller confirmed details provided by transfer agent. Caller stated the GERD and acid reflux went away after all 4 COVID-19 Vaccine. She has had 2 vaccines and 2 boosters. She stated she had a good friend who had a good friend that worked with Pfizer in the research department that recommended she tell her doctor to report that and she decided to call herself. She thought there was something in the product that resolved acid reflux problems. She was not sure if she was cured but her symptoms were gone. She stated 2 days after her first 2 shots of the COVID-19 Vaccine her acid reflux was completely gone. She could have eaten battery acid and this would not had hurt her. 4 days after her first booster COVID-19 vaccine, the acid reflux and GERD was gone and then 5 days after her 2nd booster dose of the COVID-19 Vaccine that she received last week she had no acid reflux and was gone. Reporter Type: Retired teacher. She hoped someone would find out what solved this. She just turned 76-year-old so she believed she was 74-year-old when the acid reflux and GERD went away the first time. She hesitated to even get the COVID-19 Vaccine and was afraid the vaccine would not work with her stomach problems. She did not knew how much of her situation her doctor was aware of because he was still knew to her. She stated her physician was on (address line, city, state, postal code withheld). She had her last COVID-19 Vaccine booster dose a week ago Tuesday and felt fine. She did not knew how long that would last but stated she had such a marked improvement and could breath. She was having some stomach discomfort and as the acid was pushing up in her esophagus. She stated some people had burping but she had the pushing and pressing on her chest. She also had asthma which enhanced her discomfort but all of that was completely gone. She stated the acid reflux came back again before the 2nd dose of the COVID-19 Vaccine but was gone 2 days after the COVID-19 Vaccine. Caller had no NDC, Lot number, or expiration date for the Tums, Rolaids, Pantoprazole and Nexium that did not work. She discarded the medications since the medications were not working for her acid reflux. Product Details: Dose: unknown; She was given a slip of paper from the pharmacy about her vaccine but she left the paper in her car. No additional vaccines administered on Same Date of the Pfizer Suspect. No emergency room or physician office visit required for adverse event. No prior vaccinations (within 4 weeks), within four weeks prior to the first administration date of the suspect vaccine. Adverse event following prior vaccinations: No; she has never had any. She was happy to do the report if that could help people and if that could eventually find a medication that helped with acid reflux. She asked what was in the vaccine that does calm ones stomach from the acid production. If that could help isolate what was in the vaccine, she would be happy to know. She stated she imagined if Pfizer could find a pill that actually worked then she like others would not have to watch what she eats. She stated that would be nice if Pfizer could eradicate acid reflux. Description of complaint: Pantoprazole, Nexium, Tums and Rolaids: Caller has no NDC, Lot number, or expiration date for the Tums, Rolaids, Pantoprazole, and Nexium that did not work. She discarded the medications since the medications were not working for her acid reflux. Additional lot numbers: unknown. Is a sample of the product available to be returned, if requested (Y/N): not provided. Packaging sealed and intact? not provided. Follow-up attempts are completed. No further information is expected.