This is a spontaneous report received from contactable reporters (Nurse and Consumer or other non HCP) from medical information team. A 2-year-old female patient received BNT162b2 (BNT162B2), on 02Aug2022 as dose 2, 0.2 ml single (Lot number: FP7150, Expiration Date: 30Sep2022) at the age of 2 years, in right thigh for covid-19 immunisation. The patient had no relevant medical history. There were no concomitant medications. Vaccination history included: BNT162b2 (DOSE 1, SINGLE: lot number: FT9142), administration date: 07Jul2022, when the patient was 2-year-old, for COVID-19 Immunization. The following information was reported: PRODUCT ADMINISTERED TO PATIENT OF INAPPROPRIATE AGE (non-serious), OVERDOSE (non-serious) all with onset 02Aug2022, outcome "unknown" and all described as "A Baby was given the adult Pfizer/accidently received the gray cap formulation and was administered 0.2mL/gray cap Pfizer Covid-19 vaccine that was administered to a 2 year old female"; CHILLS (non-serious), outcome "unknown"; LETHARGY (non-serious), outcome "unknown", described as "looks lethargic"; PYREXIA (non-serious), outcome "unknown", described as "fever/ fever of 103.6". Relevant laboratory tests and procedures are available in the appropriate section. Additional information: The nurse stated the product was placed in a box that was supposed to be baby Pfizer and it was assumed that it was baby Pfizer. The nurse noted not the full dose as the adult Pfizer was given, only 0.2 ml. The reporter stated, on 02Aug2022, morning they gave a vaccine out to a baby, and that was the Pfizer (clarified as Pfizer COVID 19 vaccine) and they inadvertently given them the twelve plus Pfizer instead of the infant Pfizer. Reporter asked on how do they proceed from there. So, they had given the adult Pfizer to a baby, and did they need to hold off on vaccination. It was unknown if patient received any other vaccines within 4 weeks of this vaccine. The nurse denied any other medications, medical conditions, labs, testing, or treatments for the patient relevant to these events. Patient's Medical History and Relevant Tests were reported as none. Caller provided that the information was of an off label nature and was regarding the gray cap Pfizer Covid-19 vaccine that was administered to a 2-year-old female and the parents would like to know any information on accidental administrations or if there were any studies about children receiving larger doses of the Pfizer Covid-19 vaccine. The nurse reported that the patient's caregiver (father) was on the line. He was reporting for his two year old daughter who got the adult Pfizer vaccine. He added that his daughter had fever of 103.6, chills, looking like she is almost ready to get seizures, and that she also looked lethargic. The patient's father said that she is fine now but he just wanted to know if there was information on the possible long term effects. Follow up (05Aug2022): This is a spontaneous follow-up report received from a contactable Nurse. This Nurse reported for a Patient that: Updated information included: Additional information updated. Follow-up (09Aug2022): This is a spontaneous follow-up report received from a contactable Nurse and consumer. Updated information: patient demographics (height and weight updated), Laboratory data, reaction data (events fever, chills, Lethargic were added) and clinical course details.