ALT: 39, slightly elevated; I mistakenly used sterile water for injection instead of sterile sodium chloride as the diluent for Comirnaty or the Pfizer-BioNTech COVID-19 vaccine./ 3 patients received it.; I mistakenly used sterile water for injection instead of sterile sodium chloride as the diluent for Comirnaty or the Pfizer-BioNTech COVID-19 vaccine./ 3 patients received it.; This is a spontaneous report from a contactable Nurse. A 51-year-old female patient received first dose of BNT162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Lot Number: 30145BA, Expiration date 30Nov2021), via an unspecified route of administration, administered in left arm on 30Sep2021 at 17:35 (at the age of 51 years old) as Dose 1, 0.3 ml single dose for COVID-19 immunisation. Family history was not provided. Medical history included adrenal adenoma, hypothyroidism, obesity, PCOS, Insomnia, Multiple myeloma, restrictive sleep apnea, high serum serotine, osteoporosis, osteopenia from an unknown date and unknown if ongoing. Concomitant medications were unknown reported. The patient received any other vaccines within four weeks prior to the vaccination was unknown. On 30Sep2021 the repoeter had mistakenly used sterile water for injection instead of sterile sodium chloride as the diluent for Comirnaty or the Pfizer-BioNTech COVID-19 vaccine. The reporter reported that Pfizer had not tested the effects of using sterile water for injection as the diluent for Comirnaty or the Pfizer-BioNTech COVID-19 Vaccine. The diluted vaccine using sterile water for injection as the diluent should be appropriately discarded and not used for vaccination. If the vaccine that was diluted with sterile water for injection was inadvertently administered to individuals, a definitive statement on the quality and usability of the vaccine diluted in water cannot be made. The vaccine has not been tested with sterile water for injection as the diluent. Based on this lack of information, Pfizer is unable to definitively state if the vaccine dose is valid or invalid. Therefore, we kindly refer you to (withheld) to discuss revaccination need or timing. It is not within Pfizer's remit to recommend revaccination. Reporter reported previously about the inadvertent administration of the Pfizer-Biontech Covid19 Vaccine where the vaccine was mixed with a sterile water and today reporter calling because after she have reported it, she later learned that the vaccine was pulled directly from the freezer, it was a frozen concentrated vaccine mixed with a sterile water and she wants to know if there's any different guidance on that. On 30 Sep2021 the patient underwent lab tests and procedures which included Alanine aminotransferase, blood glucose, albumin, total protein and resulted ALT was slightly elevated (39), glucose was 190, albumin was 2.8 and protein was 5.0. Reporter seriousness for used sterile water instead of sterile sodium chloride was considered as Medically significant. The patient visited physician office due to events and unknown for emergency room visit. The outcome of the events was unknown.; Sender's Comments: Based on the information available in narrative the reported  event of  Product preparation error is assessed as related to suspected vaccine BNT162B2.,Linked Report(s) : US-PFIZER INC-202101301559 same reporter, different patient/event;US-PFIZER INC-202101302700 same reporter, different patient/event