Immunomodulatory Strategies for Managing Viral Infections in Solid Organ Transplantation: Progress and Challenges

Solid organ transplantation (SOT) is a critical treatment for end-stage organ failure. Still, lifelong immunosuppression leaves recipients vulnerable to opportunistic viral infections, which can lead to severe complications such as graft dysfunction and post-transplant lymphoproliferative disorder. With emerging viral threats such as SARS-CoV-2 and arboviruses, alongside persistent challenges posed by CMV, EBV, and BKV, this review is timely in addressing the evolving landscape of post-transplant viral infections and their management. Recent studies highlight how immunosuppression impairs both innate and adaptive antiviral defenses, including diminished toll-like receptor signaling, dysfunction of NK cells, and disrupted T- and B-cell responses. Viruses exploit these deficits through immune evasion strategies, such as MHC-I downregulation and the production of immunosuppressive microRNA. Advances in management include antiviral prophylaxis, adoptive T-cell therapy, and immune monitoring, with emerging therapies like virus-specific T-cell infusions and complement inhibition showing promise. The findings underscore the need for personalized, organ-specific approaches to post-transplant care. Enhanced surveillance, vaccination strategies, and novel immunotherapies are critical in mitigating viral risks. Future research should focus on immune-risk stratification and the development of an adaptable therapeutic approach to enhance transplant outcomes in the face of evolving viral threats.