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.