Efficacy and Safety of mRNA-Based COVID-19 Vaccines in Solid Organ Transplant Recipients: A Systematic Review and Meta-Analysis

SOTRs exhibit profound hypo responsiveness to COVID-19 vaccines; however, the extreme heterogeneity observed across studies necessitates a cautious interpretation of pooled seroconversion estimates. While the data indicates a significant dose-response relationship favoring an aggressive, multi-dose strategy, the apparent safety profile may reflect under-reporting and limited follow-up rather than confirmed safety equivalence. Rare but clinically critical outcomes, such as acute allograft rejection, remain inadequately characterized in the current literature. Consequently, while the prioritization of multi-dose regimens and hybrid immunity is supported to maximize protection, clinicians must recognize that individual responses remain highly variable, and the long-term immunological impact of repeated stimulation requires further standardized investigation.