patient has inadvertently received a pediatric dose instead of an adult dose of the pfizer covid 19 vaccine on 1/31 by me. i was scheduled as a clinical lead and spent most part of the day overseeing patients that have completed vaccination and were in the waiting area. facility introduced a new vaccination log protocol, and i wanted to vaccinate patients in order to be proficient at the new system. around 1545 vaccinators packed up with the clinical site rn manager encouragement to make sure "no one gets overtime". the vaccine rotating member took all the vaccine syringes i had in the vaccine box, except for the two orange capped ones. it was 1558 when two family members and the guardian arrived at the vaccination station. patient's brother (10 years of age) was the first to get the vaccine. his weight wasn't taken, so i had to walk to the scale with him, measure and document his weight first. the guardian seemed in a rush and offered to check patient's weight for me, so they can leave sooner. additionally, they had an argument amongst them regarding the "do not disturb" feature that patient activated on his guardian's phone. lastly, patient looked below normal weight range for his age, so it didn't raise al alarm having a pediatric dose in the vaccination box at my station. the vaccine was administered, no side effects were reported