High vs.Standard Dose Influenza Vaccine in Pediatric Solid Organ Transplant (SOT) Recipients

Inclusion Criteria: 1. Male or female, 3-17 years of age at time of enrollment 2. Pediatric kidney, heart, and/or liver transplant recipient ≥1 month and \<24 months post-transplant at the time of study immunization * Note: Inclusion of recipients of multiple organs is permitted but is limited to recipients of any combination of organs including kidney, heart and/or liver * Note: Participants undergoing re-transplantation are permitted 3. Anticipated to be available for duration of the study 4. Available by telephone, email, or text message Exclusion Criteria: 1. Inability (i.e. not able to understand and provide consent) or unwillingness of a participant/parent/legal guardian to give written informed consent or comply with study protocol 2. History of severe hypersensitivity to influenza vaccination or anaphylaxis to eggs/egg protein 3. History of severe latex hypersensitivity 4. History of Guillain-Barre syndrome 5. History of lung or intestine transplant 6. HIV positive patients (testing within 24 months of enrollment) 7. Receipt of current season's influenza vaccine post-transplant prior to enrollment in the study 8. Currently pregnant or lactating (females of childbearing age may be enrolled based on self-report, urine pregnancy test must be performed prior to each influenza vaccine) 9. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.