Incidence and severity of SARS-CoV-2 infections in liver and kidney transplant recipients in the post-vaccination era: Real-life data from Denmark

Abstract

Coronavirus disease 2019 (COVID‐19) caused by SARS‐CoV‐2 has been associated with a high risk of adverse outcomes in solid organ transplant (SOT) recipients in the pre‐vaccination era. In this retrospective cohort study, we examined the incidence and severity of COVID‐19 in kidney and liver transplant recipients in Denmark in the post‐vaccination era, from December 27, 2020, to December 27, 2021. We included 1428 SOT recipients with 143 cases of first‐positive SARS‐CoV‐2 PCR test. The cumulative incidence of first‐positive SARS‐CoV‐2 PCR test 1 year after initiation of vaccination was 10.4% (95% CI: 8.8–12.0), and the incidence was higher in kidney than in liver transplant recipients (11.6% [95% CI: 9.4–13.8] vs. 7.4% [95% CI: 5.1–9.8], p = .009). After the first‐positive SARS‐CoV‐2 PCR test, the hospitalization rate was 31.5% (95% CI: 23.9–39.1), and 30‐day all‐cause mortality was 3.7% (95% CI: 0.5–6.8). Hospitalization was lower in vaccinated than in unvaccinated SOT recipients (26.4% [95% CI: 18.1–34.6] vs. 48.5% [95% CI: 31.4–65.5], p = .011), as was mortality (1.8% [95% CI: 0.0–4.3] vs. 9.1% [95% CI: 0.0–18.9], p = .047). In conclusion, SOT recipients remain at high risk of adverse outcomes after SARS‐CoV‐2 infections, with a lower risk observed in vaccinated than in unvaccinated SOT recipients.

COVID-19-associated liver injury: Clinical characteristics, pathophysiological mechanisms and treatment management

“…In contrast, median antibody levels and seroconversion rates increased 9-fold in 60% of non-responders after four doses of vaccine [159] . Although immunocompromised patients have a lower humoral response triggered by vaccination, the risk of infection, severe disease, and death is greatly reduced in vaccinated organ transplant recipients compared with unvaccinated organ transplant recipients [160] , [161] . In addition, older age, short-term liver transplantation and use of antimetabolites (e.g., mycophenolate mofetil) are related factors that lead to ineffective vaccination of LT recipients [162] , [163] .…”

Comparison of outcomes in vaccinated versus unvaccinated COVID‐19 kidney transplant recipients, a single center retrospective study—Is the taboo justified?

“…9 Hamm et al examined the outcomes of COVID-19 infections in kidney and liver transplant recipients from December 2020 to December 2021. 10 They included 1428 SOT with 143 cases of first-positive SARS-CoV-2 PCR test. 10 The cumulative incidence of the SARS-CoV-2 PCR test was 10.4%, with a higher incidence in kidney than liver (11.6% vs. 7.4%, p = .009).…”

“…10 Both studies are from outside the US; thus, the type of vaccines differ. 10 Our study focused on patients with recent transplants (transplanted <2 years ago) during the most intense immunosuppression exposure. In con-trast, the above studies included patients 2.5-3 years (upto 10 years) post-transplant when they had the first positive SARS-CoV-2 PCR.…”

“…In con-trast, the above studies included patients 2.5-3 years (upto 10 years) post-transplant when they had the first positive SARS-CoV-2 PCR. 9,10 Ours is the longest follow-up (6-20 months) of KTx recipients. Our study has included patients through 4/30/2022 and followed them until 10/31/2022, making it most reflective of the current situation.…”

“…4,5 Our study builds on previous studies that compared data in SOT recipients based on their COVID-19 vaccination status. [9][10][11][12] Our study differs from previous studies as it has a longer follow-up period and includes transplant recipients earlier in the post-transplant period when immunosuppression is highest. 13 After March 2020, we modified our induction protocol regardless of vaccination status.…”