Background: The mortality rate of coronavirus disease 2019 (COVID-19) in kidney transplant recipients (KTR) has significantly decreased with the implementation of vaccination programs. However, information on factors influencing poor outcomes in KTR diagnosed with COVID-19 and the real-world impact of booster vaccinations, particularly in Eastern countries, is still limited.
Methods: The Thai Transplant Society conducted a prospective multicenter cohort registry, including KTR diagnosed with COVID-19. The study aimed to examine incidence and factors associated with poor COVID-19 outcomes and complications, including death, COVID-19 pneumonia, and superimposed bacterial infection.
Results: A total of 413 KTR with COVID-19 from 17 transplant centers were included. The COVID-19 mortality rate was 5.6% and the incidence of pneumonia was 18.8%. With each 10-year increase in age, the risk of death, pneumonia, and bacterial infection increased by 68%, 83%, and 51%, respectively. Completing the primary vaccination (two-dose) reduced the odds of death by 76% and pneumonia by 88% compared to unvaccinated KTR. Receiving a booster dose (third or fourth dose) further reduced the odds of death by 93%, pneumonia by 97%, and bacterial infection by 92% compared to unvaccinated individuals. There were no significant differences in the effectiveness of inactivated, viral vector, and mRNA vaccine in preventing COVID-19-related deaths among KTR who completed the primary vaccination. No specific immunosuppressants were associated with inferior outcomes of COVID-19.
Conclusions: The mortality and complications of COVID-19 were decreased in KTR during the national immunization phase. Administering booster vaccinations is strongly recommended to reduce disease severity and mortality among KTR.