Real-world effectiveness of COVID-19 vaccination in liver cirrhosis: a systematic review with meta-analysis of 51,834 patients.

SARS-CoV-2 vaccinations were found to be highly effective in phase 3 clinical trials. However, these trials have not reported data regarding the subgroup of liver disease or excluded patients with liver disease. The effectiveness of COVID-19 vaccines among liver cirrhosis (LC) patients is unclear. We conducted this meta-analysis to assess the effectiveness of SARS-CoV-2 vaccination in LC patients. A comprehensive literature search was conducted to include all the relevant studies that compared the outcomes of LC patients who received SARS-CoV-2 vaccines vs. unvaccinated patients. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated by the Mantel-Haenszel method within a random-effect model. Four studies with 51,834 LC patients (20,689 patients received at least one dose vs 31,145 were unvaccinated) were included. COVID-19-related complications, including hospitalization (RR 0.73, 95% CI 0.59-0.91, P  = 0.004), mortality (RR 0.29, 95% CI 0.16-0.55, P  = 0.0001), and need for invasive mechanical ventilation (RR 0.29, 95% CI 0.11-0.77, P  = 0.01), were significantly lower in the vaccinated group compared to the unvaccinated group. SARS-CoV-2 vaccination in LC patients reduced COVID-19-related mortality, intubation, and hospitalization. SARS-CoV-2 vaccination is highly effective in LC. Further prospective studies, preferably randomized controlled trials, are necessary to validate our findings and determine which vaccine is superior in patients with LC.