Association Between SARS-CoV-2 Messenger RNA Vaccines and Lower Infection Rates in Kidney Transplant Recipients : A Registry-Based Report.

BACKGROUND:The real-world protection provided by SARS-CoV-2 messenger RNA (mRNA) vaccines to kidney transplant recipients (KTRs) remains uncertain. OBJECTIVE:To study the association between mRNA vaccination and SARS-CoV-2 infection rate in KTRs. DESIGN:Retrospective observational cohort study. SETTING:The Czech Republic (17 February to 16 May 2021). PATIENTS:2101 KTRs followed in the Department of Nephrology at the Institute for Clinical and Experimental Medicine. MEASUREMENTS:Positive result for SARS-CoV-2 on polymerase chain reaction test and vaccination status of KTRs. RESULTS:The incidence rate in the vaccinated group was 0.474 per 1000 person-days (33 cases in 69 672 days at risk). The incidence rate in the unvaccinated group was 1.370 per 1000 person-days (79 cases in 57 658 days at risk). The unadjusted incidence rate ratio (IRR; incidence rate of vaccinated/incidence rate of unvaccinated) for KTRs was 0.346 (95% CI, 0.227 to 0.514). The multivariable adjusted IRR for KTRs was 0.544 (CI, 0.324 to 0.876). LIMITATION:Retrospective observational design, uneven follow-up of patient groups, and different exposition to SARS-CoV-2 stemming from strong temporal trends and differences in clinical and probably behavioral characteristics. CONCLUSION:Vaccination of KTRs is associated with lower risk for SARS-CoV-2 infection. PRIMARY FUNDING SOURCE:The Ministry of Health of the Czech Republic.