Diverticulitis; She was not able to get the second dose because she was still home on antibiotics and wasn't well.; UTI; she was still in pain; This is a spontaneous report from a Pfizer-sponsored program. A contactable consumer (patient) reported that a 72-year-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE) via an unspecified route of administration, administered in arm right on 10Mar2021 09:30 (Batch/Lot number was not reported) as 1st dose, single for covid-19 immunisation.  The patient medical history was not reported. There were no concomitant medications. She did not have any other vaccinations the same day as her Pfizer COVID-19 vaccine or in the four weeks prior. The patient received the first dose of the vaccine on 10Mar2021. Her vaccine card was handwritten, she couldn't really read what was handwritten for the LOT, it could be SNG207, but she was not sure she was reading it right, it also could be 7NG207, she couldn't read it. Yesterday (18May2021) she got tested for antibodies and had none. She got both the POC rapid and blood test and both were negative. After the first dose she was hospitalized on 29Mar2021 for diverticulitis (in Mar2021) and was given many different antibiotics. She was discharged she thought on 31Mar2021, she was there maybe two days. She said recovery took a while, they had her on long rounds of antibiotics. She thought though that she went for her Pfizer COVID-19 vaccine injection 10Mar2021, then was seen in PRIVACY on 12Mar2021, and she thought she had a UTI and put her on Cipro then two days later she was still in pain (Mar2021) so they put her on Keflex for a week and she was still in pain so she went to another doctor who put her on Amoxicillin, so she had a lot of antibiotics after getting the shot, then she was in the hospital for diverticulitis. Then she was on metronidazole (FLAGYL) and ciprofloxacin (CIPRO) medications IV while she was in the hospital for diverticulitis, and then she came home on Cipro and Flagyl for four more days, until the night her mouth started to swell so she stopped taking them because she thought she was having a reaction (AER#2021571213). She then took an unknown antibiotic that she only took it for one day before she stopped it, then she got a CAT scan that said she was ok (unknown date). She clarified that for the unknown antibiotic she stopped after she took one pill because she had a reaction and then said she was done. She said all that time she was supposed to get the second dose, while she was in hospital and then was told to wait until she was better. She thought she must have some antibodies, so she got tested and had none. She was checked and tested for some percentage of antibodies since after her first dose it said she should have 70-80% and she was unable to get her second dose. She said that the test said she had no antibodies, it was totally negative, and she would like to know is that normal. She was not able to get the second dose because she was still home on antibiotics and wasn't well. She is unsure if that sickness was from the shot or not and does not know if she should start her first dose over again at this point (she did not ask a question regarding this). Patient underwent Ig/IgM Rapid POC test and SARS-COV2 Ig anti-spike test and both revealed negative result on 18May2021. Outcome of diverticulitis was not recovered, outcome of other events was unknown.    Information on the lot/batch number has been requested.