Lessons From COVID-19 on Inborn Errors of Immunity: A Five-Year Narrative Review.

COVID-19 research now provides a coherent picture of the virus's immunological impacts, highlighting immune-evasion mechanisms, the particular vulnerabilities of patients with inborn errors of immunity (IEI), and evolving therapeutics for severe disease. SARS-CoV-2 exploits ACE2 for cell entry and can utilise CD147 to infect immune cells, undermining antiviral defences; recent work details cytokine storm biology, NLRP3 inflammasome activation, and suppression of type I interferon responses. IEI patients are disproportionately affected, often with severe, prolonged courses and persistent PCR positivity. Therapeutic approaches such as convalescent plasma, anti-cytokine agents interferon alpha-2b, and plasma exchange show variable effectiveness, while vaccine performance is challenged by ongoing viral evolution. Together, these insights underscore the need for tailored treatment strategies for IEI populations, vigilant monitoring for immune-escape variants, and continuous adaptation of therapeutic and preventive measures. The aim of this review is to synthesise these findings, evaluate their implications for clinical management, and highlight future directions for research and patient care.