We aimed to investigate the variation in mortality from SARS-CoV-2 infection in kidney transplant recipients in the Bronx, New York since the beginning of the pandemic. Between March 16, 2020 and March 14, 2022, 499 patients were diagnosed with SARS-CoV-2 infection by RT-PCR. 58.8% were male, median age 59 years old (IQR: 46-67), predominantly Hispanic (50.1%) and African American (28.7%). 74.6% received a deceased-donor renal transplant, 46% received anti-thymocyte induction. Most patients were on triple immunosuppression (96% on calcineurin inhibitors, 87% on anti-metabolite, and 98% on prednisone). While the mortality rate was 37 % (47/128) in patients during first peak between March 16 and April 30, 2020, it has significantly decreased to 11% (7/61) from May 1, 2020 to end of December 2020 with social distancing and use of facemask. Between January 1, 2021 and November 5, 2021 with use of vaccination and monoclonal antibodies, the mortality rate further decreased to 7.7% (10/129). Between November 6, 2021 till March 14, 2022 which corresponds to the period when the Omicron variant was prevalent, the mortality rate was 6.6% (12/181). Among those diagnosed during the period when Omicron was prevalent, 156/181 (86%) have received 2 doses of COVID vaccine and 67/181 (37%) have received a third dose. Mortality was 6.4% in vaccinated patients and 4.7% in non-vaccinated patients. Since the beginning of use of monoclonal antibodies in mild cases not requiring hospitalization, 76 patients received a combination of casirivimab/imdevimab when initial SARS-CoV-2 variants were dominant and sotrovimab during the period of Omicron. Only one death occurred in patients who received monoclonal antibody treatment. We identified a total of 19 re-infections. Most of re-infected patients have already received at least 2 doses of COVID vaccine. 7/19 (37%) were hospitalized but none of them died.
In summary, mortality from SARS-CoV-2 infection in kidney transplant recipients was higher earlier at the pandemic and has significantly decreased over time. This could be explained by initial exposure of the patients with higher viral load due to lack of personal protection and social distancing. However, since the judicious use of monoclonal antibodies and vaccination, in addition to social distancing protocols and use of facemask, the mortality in kidney transplant recipients has decreased over time.