Therapeutic potential of mesenchymal stromal cells in COVID-19: a meta-analysis of clinical trials conducted since the pandemic onset

• MSC therapy significantly reduced all-cause mortality in moderate to critical COVID-19 patients (OR=0.74, 95% CI 0.55–0.99) with low heterogeneity and no publication bias. • The meta-analysis included 24 comparative studies (13 RCTs and 11 non-randomized trials) with 1080 patients, providing robust evidence for MSC safety and efficacy. • Subgroup analyses by disease severity, administration route, dosing frequency, and study design revealed consistent benefits, supporting MSC therapy as an adjunctive treatment. • The findings suggest potential applicability of MSC therapy to other respiratory viral pneumonias, addressing an urgent need for novel therapeutic strategies.