Critical role of vaccination in preventing severe coronavirus disease 2019: perspectives from clinical outcomes in an Australian kidney transplant recipient cohort
Dhakshayini Tharmaraj, Paayal Naidu, Mohana Baptista, Sarah McBride, Rhonda Stuart, Claire Dendle, Kevan R. Polkinghorne, William R. MulleyAbstract
Background
Kidney transplant recipients (KTRs) disproportionately experience severe COVID‐19 infections. We previously identified concern regarding vaccine‐induced rejection as a barrier to vaccine uptake.
Aim
This study assesses COVID‐19 vaccine uptake, infection outcomes and allograft rejection in KTRs during the delta and omicron waves (BA.1/BA.2).
Methods
This cohort study included all adult KTRs with a functioning allograft at 22 March 2021 at our centre. KTR and vaccination‐related risk factors for the primary outcome of severe COVID‐19 infection (requiring hospitalisation) and the secondary outcomes of death and all COVID‐19 infections were assessed using Cox proportional hazards models. Rejection risk following infection/vaccination was also assessed.
Results
Of the 986 included KTRs, there were 333 (33.8%) COVID‐19 infections, 79 (23.7%) severe infections and 13 deaths ( n = 13/333, 3.9%). Vaccine number was the most significant modifiable predictor of severe infection (adjusted hazards ratio, per additional dose, 0.5; 95% confidence interval, 0.40–0.65, P < 0.001) and death. While older age also predicted severe infection and death, lower estimated glomerular filtration rate, history of diabetes and previous allograft rejection predicted severe infection. Male gender was the only predictor of all infections. Mycophenolate dose, prednisolone use and vaccine type did not predict infection or severe disease. Infections and vaccinations did not increase the risk of rejection.
Conclusions
KTRs should be encouraged to be optimally vaccinated to prevent severe disease and can be reassured about the low risk of allograft rejection. Risk factors that compound the state of immunocompromise and severe COVID‐19 infections should prompt vigilance and targeted interventions to mitigate these risks.