3 children were given booster doses of the orange cap that were not diluted; 3 children were given booster doses of the orange cap that were not diluted/ vaccine was not appropriately diluted.; Fever; Achiness; More robust immune response; This is a spontaneous report received from contactable reporter(s) (Nurse and Physician) from medical information team.  A 7-year-old male patient received BNT162b2 (BNT162B2), on 26Aug2022 at 15:30 as dose 3 (orange cap; booster) 0.2ml, single (Lot number: FL8094, Expiration Date: 31Aug2022) at the age of 7 years intramuscular, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Asthma" (unspecified if ongoing), notes: Pertinent details: Mild/ related to illness; "Food allergies" (unspecified if ongoing); "Seasonal allergies" (unspecified if ongoing). Concomitant medication(s) included: ALBUTEROL [SALBUTAMOL] taken for asthma; ZYRTEC [CETIRIZINE HYDROCHLORIDE] oral taken for hypersensitivity. Vaccination history included: BNT162b2 (DOSE: 1, SINGLE, Time: 04:34 PM, Anatomical site of injection: Left Arm, Route of administration: Intramuscular, Lot: FK5127), administration date: 09Nov2021, when the patient was 6-year-old, for COVID-19 Immunization; BNT162b2 (DOSE: 2, SINGLE, Time: 03:19 PM, Anatomical site of injection: Left Arm, Route of administration: Intramuscular, Lot: FK5127), administration date: 03Dec2021, when the patient was 6-year-old, for COVID-19 Immunization. The following information was reported: IMMUNISATION REACTION (non-serious) with onset 2022, outcome "unknown", described as "More robust immune response"; PAIN (non-serious) with onset 26Aug2022, outcome "recovered" (2022), described as "Achiness"; PYREXIA (non-serious) with onset 26Aug2022, outcome "recovered" (2022), described as "Fever"; OVERDOSE (non-serious) with onset 26Aug2022 at 15:30, outcome "unknown", described as "3 children were given booster doses of the orange cap that were not diluted"; PRODUCT PREPARATION ERROR (non-serious) with onset 26Aug2022 at 15:30, outcome "unknown", described as "3 children were given booster doses of the orange cap that were not diluted/ vaccine was not appropriately diluted.". Therapeutic measures were not taken as a result of pyrexia, pain. Therapeutic measures were taken as a result of immunisation reaction.  Another reporter (Health Care professional) considered "3 children were given booster doses of the orange cap that were not diluted" and "3 children were given booster doses of the orange cap that were not diluted/ vaccine was not appropriately diluted." as related to BNT162b2.  Additional information: Booster dose (Other). Prior vaccination (within 4 weeks): None. Relevant tests: None. Specific relevant test for thromboembolic events with thrombocytopenia: None. AE term: Fever Achiness, Onset time: within 1-2 hrs of vaccine, Seriousness criteria: not-serious. Please clarify the type of medication error: the medication/vaccine was not appropriately diluted. Please provide the stage of medication error (e.g., prescribing, dispensing, preparation, and administration): Preparation error. Please provide contributing factors to the medication error: Busy day, no staff available for help, other vaccines being used are pre-diluted. Please clarify if the medication error affected the patient or consumer with clinical consequences: Yes- lead to more robust immune response. Please provide the details of hospitalization: N/A. Please provide the details of treatment received as well as any clinical evolution: Treated at home with OTC medications.  Follow-up (06Sep2022): Follow-up attempts are completed. No further information is expected.  Follow-up (17Oct2022): This is a spontaneous follow up report from a contactable Physician. This Physician reported for the patient in response to HCP letter [sent to physician] via follow-up letter which included that: Updated information included: Reporter details (alternate phone number, suffix, department, health care professional selected as yes and PC, CC check-box unchecked to make as true reporter), historical vaccines details (time, route , anatomical site and lot added in notes), new relevant medical history (asthma, food allergy, seasonal allergy), suspect details (dose start and stop time, vaccination facility name and phone number), new concomitant medications, new events (Fever, Ache, Immunisation reaction), event details (onset time of events Overdose and Product concentrate, event causality and clinical information.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202201099703 Same drug/event, different patient.;US-PFIZER INC-202201099704 Same drug/event, different patient.;