Clinical effectiveness of COVID-19 vaccination in solid organ transplant recipients

We aimed to assess the incidence rate of coronavirus disease 2019 (COVID-19) in vaccinated versus unvaccinated solid organ transplant recipients (SOTR) at our center.

We abstracted the following clinical data from our transplant registry from 1/1/2021 to 6/2/2021: demographics, details of COVID-19 vaccination, incidence of COVID-19, and related mortality. We calculated incidence of symptomatic COVID-19 per 1000/person days at risk and incidence rate ratio (IRR).

Among 2151 SOTRs, 912 were fully vaccinated, and 1239 were controls (1151 unvaccinated, 88 partially vaccinated). Almost 70% of vaccinated subjects received the mRNA-1273 vaccine. There were 65 cases of COVID-19 that occurred during the study period - four occurred among fully vaccinated individuals and 61 among controls (including two in partially vaccinated individuals). Incidence rate for COVID-19 was 0.065 (95% CI 0.024-0.17) per 1000 person days in vaccinated versus 0.34 (95% CI 0.26-0.44) per 1000/person days in the control group; IRR was 0.19 (95% CI 0.049 -0.503, p < 0.005). There were no COVID-19 related deaths in the four breakthrough infections and two of 61 (3.3%) among controls.

We demonstrate real world clinical effectiveness of COVID-19 vaccination in SOTRs with an almost 80% reduction in the incidence of symptomatic COVID-19 versus unvaccinated SOTRs during the same time.