fever; chills; vomiting; weakness; headache; cough; trace- pleural effusion; who received the entire vial of the undiluted Pfizer COVID vaccine; received the entire vial of the undiluted Pfizer COVID vaccine/The entire vial was administered all 6 doses in the right deltoid; This is a spontaneous report from a contactable nurse and a physician. The nurse reported similar events for two patients. This is one of the two reports. Only this case is serious. A 46-year-old male patient received second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), via an unspecified route of administration at the age of 46 years old, administered in right deltoid on 12May2021 (Lot Number: EW0168; Expiration Date: Aug2021) at single dose for COVID-19 immunization. Medical history included ongoing CRD on hemodialysis since 25Sep2017, ongoing Polycystic kidney, ongoing HTN, ongoing Brain aneurysm, ongoing GERD, ongoing Seizure disorder; Fever, nausea, vomiting, sepsis, Secondary hyperparathyroidism. Family history included Polycystic kidney disease- brother/father/uncles. Concomitant medications included ongoing allopurinol, ongoing paracetamol (TYLENOL), ongoing amlodipine, ongoing cholecalciferol, hydralazine, metoprolol, vitamins nos (MVI), phenytoin. Historical Vaccine included first dose of BNT162B2 on 21Apr2021 (Lot number ER8736, Expiration date Jul2021) at the age of 46 years old, administered in right deltoid for COVID-19 immunization. The nurse reported a medication error for two patients who received the entire vial of the undiluted Pfizer COVID vaccine on 12May2021. The entire vial was administered all 6 doses in the right deltoid. The reporter did not provide specific signs and symptoms. They were in their care after the vaccine was given for an hour and was sent home. They were instructed for any signs and symptoms to report to ER immediately. The patient also experienced fever/chills, vomiting, weakness, headache and cough, all on 12May2021 which were caused emergency room visit and hospitalization from 13May2021 to 15May2021 with treatment unknown. Lab data included CXR on 13May2021 with result: trace- pleural effusion. The outcome of the events were unknown.  Follow-up (25May2021): new information received from a contactable physician included: new reporter-physician added, medical history and concomitant medications added, lab data added, vaccination on 12May2021 is updated as second dose and Historical Vaccine with first dose of BNT162B2 added, new events "fever/chills, vomiting, weakness, headache and cough, trace- pleural effusion" added and case upgrade to serious.  No follow-up attempts are needed. No further information is expected.; Sender's Comments: As there is limited information in the case provided, the causal association between the event and the suspect drug cannot be excluded. The case will be reassessed once new information is available.   The impact of this report on the benefit/risk profile of the Pfizer drug is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees, and Investigators, as appropriate. ,Linked Report(s) : US-PFIZER INC-2021540031 Same reporter/product, similar events, different patient