Abstract External IDs PubMedCentral PMC8549130 Keywords Adult, Aged, Antibodies, Viral/blood, BNT162 Vaccine, COVID-19/immunology, COVID-19 Vaccines/administration & dosage, Female, Graft Rejection/immunology, Humans, Immunity, Cellular/drug effects, Immunity, Humoral/drug effects, Immunization, Secondary/statistics & numerical data, Immunosuppressive Agents/administration & dosage, Kidney Transplantation/adverse effects, Male, Middle Aged, SARS-CoV-2/immunology, Transplant...