Patient presented to the clinic for her second dose of a COVID-19 vaccine on 4/6/2022, accompanied by her father and 2 older sisters. She was seated at the Pfizer table with her family and received an adult-formulation dose of Pfizer (Lot# FM0698) to her LD.   The vaccinator, a MA, reports that she realized that the client should have received the pediatric formulation of Pfizer instead of the adult formulation immediately after completing the vaccination. She then reported the situation to the charge nurse, a RN, who called Dr. and informed him of the situation and its circumstances. Dr. instructed RN to advise the family of the increased risk for flu-like symptoms and to closely monitor for s/s myocarditis and pericarditis.   The client and her father were immediately notified of the occurrence and educated on the increased risk for flu-like symptoms and to closely monitor for myocarditis or pericarditis. They were also educated on how to recognize signs and symptoms of myocarditis and pericarditis and when to seek out medical attention, other potential adverse effects and how to treat them, and on how to recognize signs and symptoms of allergic reactions and when to seek medical attention.   The client and her father verbalized understanding and reported that the client has no history of severe allergies or previous adverse vaccine reactions. During the observation period, the client remained at baseline and reported no new onset symptoms following the vaccine administration. She left accompanied by her family in a private vehicle after her observation period.  After being notified of the situation, this writer engaged the vaccinator in a conversation regarding the occurrence. She reported that she followed the standard process of verifying the client?s age and which vaccine was being administered to the client, but that she "didn't make the connection" that she was proceeding in error. She stated that she realized that the vaccine that had been administered was inappropriate for the client?s age immediately after completing the vaccination and that she believes that feeling rushed was a contributing factor to the error.   This writer coached the vaccinator to be very careful when vaccinating and to evaluate the DOB of the client/the client?s age to ensure that the vaccine being administered is appropriate for the client. She was advised to follow all of the standard safety check processes currently in place in a meaningful way so that she can identify potential errors and stop before they happen. (Verbally confirm the client?s name and DOB, state their age aloud, verbally confirm which vaccine they are going to receive, verbally confirm which vaccine is selected in the dropdown menu for documentation, show the vaccine syringe to the client and/or the adult accompanying the client and indicate which vaccine it is and what the dosage is by pointing to the label and how much vaccine is in the syringe). She was encouraged to identify feeling rushed as a trigger to work even more deliberately.  Vaccinator agreed to all of the points above. She reports that she will be scrupulous about identifying the age of the client and the appropriateness of the vaccine to be administered and will verbally confirm these points out loud (per the existing procedure described above). She also agrees to be primarily moved to the Moderna station, but if conditions require her to work in the Pfizer adult or Pfizer pediatrics stations, she agrees that she will not cross between the two types of Pfizer on any given day. She has agreed to slow down and be extra careful when she?s feeling rushed. Vaccinator has been observed several times since the occurrence and has been noted to be correctly following all safety checks/procedures.  The charge RN also spoke to the staff member who directed the clients to the inappropriate table, and educated her to be sure to screen all clients for their age and to direct clients to the appropriate table for the vaccination type they are to receive. She verbalized understanding and reported that she will be diligent and scrupulous on this matter in the future. She also has been observed since the occurrence and has been seen to follow correct procedures. The issue was addressed in the end-of-day huddle for the benefit of all staff members.