Background and Aims Detailed information on the immune response after second vaccination of cirrhotic patients and liver transplant (LT) recipients against SARS-CoV-2 is largely missing. We aimed at comparing the vaccine-induced humoral and T-cell responses of these vulnerable patient groups. Methods In this prospective cohort study, anti-SARS-CoV-2 spike-protein titers were determined using the DiaSorin LIAISON (anti-S Trimer) and Roche Elecsys (anti-S RBD) immunoassays in 194 patients (141 LT, 53 cirrhosis Child-Pugh A-C) and 56 healthy controls before and 10-84 days after second vaccination. The spike-specific T-cell response was assessed using an IFN-γ release assay (IGRA, EUROIMMUN). A logistic regression analysis was performed to identify predictors of low response. Results After the second vaccination, seroconversion was achieved in 63% of LT recipients and 100% of cirrhotic patients and controls using the anti-S Trimer assay. Median anti-SARS-CoV-2 titers of responding LT recipients were lower compared to cirrhotic patients and controls (p<0.001). Spike-specific T-cell response rates were 36.6%, 65.4%, and 100% in LT, cirrhosis, and controls, respectively. Altogether, 28% of LT recipients did neither develop a humoral nor a T-cell response after second vaccination. In LT recipients, significant predictors of absent or low humoral response were age >65y (OR: 4.57, 95%-CI 1.48-14.05) and arterial hypertension (OR: 2.50, 95%-CI 1.10-5.68), whereas vaccination failure was less likely with calcineurin inhibitor monotherapy than with other immunosuppressive regimens (OR: 0.36, 95%-CI 0.13-0.99). Conclusion Routine serological testing of the vaccination response and a third vaccination in patients with low or absent response seem advisable. These vulnerable cohorts need further research on the effects of heterologous vaccination and intermittent reduction of immunosuppression before booster vaccinations.

The extent of monkeypox virus environmental contamination of surfaces is unclear. We examined surfaces in rooms occupied by two monkeypox patients on their fourth hospitalisation day. Contamination with up to 105 viral copies/cm2 on inanimate surfaces was estimated by PCR and the virus was successfully isolated from surfaces with more than 106 copies. These data highlight the importance of strict adherence of hospital staff to recommended protective measures. If appropriate, pre-exposure or early post-exposure vaccination should be considered for individuals at risk.