Keywords: antibody response; COVID-19; longitudinal analysis; organ transplant; vaccination EN antibody response COVID-19 longitudinal analysis organ transplant vaccination 520 523 4 03/16/23 20230401 NES 230401 Dear Editor, An updated understanding of how immunity may wane or be sustained following SARS-CoV-2 vaccination is needed to guide efforts aimed at mitigating the ongoing risks from COVID. IgG-N and IgG antibodies to the receptor-binding domain of the S1 subunit of the spike protein (IgG-S) were measured serially using the Abbott SARS-CoV-2 IgG II assay [[6]]. SARS-CoV-2 infections were adjudicated based on available polymerase chain reaction (PCR) test results, verified self-reports, and elevated immunoglobulin G (IgG) antibodies to the nucleocapsid protein (IgG-N) [[5]]. [Extracted from the article]