This is a spontaneous report received from a contactable reporter(s) (Physician) from medical information team, Program ID: (Unknown). A female patient received BNT162b2 (BNT162B2), in Dec2021 as dose 1, single (Batch/Lot number: unknown), in Jan2021 as dose 2, single (Batch/Lot number: unknown), in Sep2021 as dose 3 (booster), single (Batch/Lot number: unknown) and in Apr2022 as dose 4 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "obesity" (ongoing); "hypertension" (ongoing). There were no concomitant medications. The following information was reported: DRUG INEFFECTIVE (medically significant), COVID-19 (medically significant), outcome "unknown" and all described as "received a total of 4 doses of the Pfizer COVID-19 vaccine and tested positive for Covid-19 4 months from patient's last dose of the vaccine". The patient underwent the following laboratory tests and procedures: SARS-CoV-2 test: Positive, notes: Patient received a total of 4 doses of the Pfizer COVID-19 vaccine and tested positive for Covid-19 4 months from patient's last dose of the vaccine. Therapeutic measures were taken as a result of drug ineffective, covid-19. The ID number of COVID-19 vaccine was unknown. Clinical course: Caller declined to provide transfer agent with additional reporter details such as an address because caller has been transferred 4 times already and has provided that information already before. Caller is calling because caller didn't warn caller's patients that caller's patients would be ineligible for future boosters if patients were to take Paxlovid. Caller did not specify what boosters caller is referring to, no specific product mentioned in regards to boosters. Caller's sister tested positive for Covid-19, and caller's sister's physician told caller's sister that caller's sister would ineligible for future boosters if caller's sister were to take Paxlovid. Caller did not specify what boosters caller is referring to, no specific product mentioned in regards to boosters. Caller wanted to confirm if this is true or not. Upon transfer caller confirmed details provided by transfer agent, clarifying that the boosters caller is referring to are the Pfizer COVID-19 vaccine boosters that may come out in the future, this fall, for other Covid variants that may have better efficacy against the more recent Covid variants that have developed. Caller confirmed caller's sister, the patient, has not been prescribed Paxlovid and has not taken Paxlovid. Has been on this call for long time now, caller has provided caller's information 4 or 5 times now. Caller doesn't mind providing the information to call handler because caller can understand call handler and caller handler does not have a thick accent. Confirmed caller does not have Paxlovid with caller, caller was reading the information on the Paxlovid package insert which caller read online on the Pfizer website. The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received. Sender's Comments: The efficacy of a drug varies from patient to patient and can be affected by different factors; however, a contributory role of the suspect product to the reported event Drug effect incomplete cannot be ruled out.