heart transplant rejection; leg swelling, like really bad scary swelling; trouble breathing; he could have gotten the Covid 19 virus; he could have gotten the Covid 19 virus; This is a spontaneous report from a contactable consumer (daughter-in-law). A 79-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, solution for injection), dose 2 via an unspecified route of administration on an unspecified date (Batch/Lot number was not reported) (at the age of 78-years-old) as DOSE 2, SINGLE and dose 1 via an unspecified route of administration on an unspecified date (Batch/Lot number was not reported) (at the age of 78-years-old) as DOSE 1, SINGLE for COVID-19 immunisation. Medical history included heart transplant and congestive heart failure. Concomitant medications included unspecified pills for the transplant. Historical vaccine included flu vaccine. The reporter (patient's daughter-in-law) heard from her husband that her father-in-law received the Covid 19 vaccine. Her father-in-law had a heart transplant over 10 years ago. Now he was having a heart transplant rejection and according to his doctor it was because of the Covid 19 vaccine. The patient was 78 years old when he received the Covid 19 vaccine. She thought he received the covid-19 vaccine early this year (2021) or late last year (2020). He was signed up to receive the covid-19 vaccine as soon as he could get it. She has not spoken to her father-in-law directly as he had been too ill. When probed for the Covid 19 vaccine information the she reported that she does not know the dates her father-in-law received the Covid 19 vaccines. She does not have the NDC/Lot/Expiry for either dose. She was sure it was a Pfizer product. When probed for medical history and concomitant medications she reported that before the heart transplant the patient had congestive heart failure. She does not know if he still has that or not. He also takes a thousand pills for the transplant but she does not have that information.  She reported he received his heart transplant over 10 years ago from a 25-year-old female who had cytomegalovirus. He was taking medications for that also. She stated that her father-in-law was in the hospital for at least 4 days. He came home on a Tuesday. He spent the weekend in the hospital. It may have been last week or the week before. She was not sure. She clarified that the patient received his covid-19 vaccines at a mass vaccination site. She first learned about this information from her husband on last Friday, 23Jul2021. Her husband did not want her to tell anyone.  She thought the patient had some leg swelling, like really bad, scary swelling. She does not know which leg was affected. She also thinks he had some trouble breathing.  She thinks the doctor said he might be able to get the patient's medications under control, so the rejection is reversed.  When probed about adverse events with any other vaccine she reported that she does not think he had any adverse events. He never complained to her about it, like the flu vaccine, no complaints. The reporter commented that she had not heard that the covid 19 vaccine could cause this nor have potential to cause this. She stated that the patient could have gotten the covid-19 virus, the heart rejection could have been caused by anything. Ten years after the heart transplant to be rejected, this was odd. The patient was hospitalized for heart transplant rejection and leg swelling, like really bad scary swelling for 4 days. Relevant tests were unknown. The outcome of the events was unknown.  Information on the lot/batch number has been requested.