Human Type‐I Interferon Omega Holds Potent Antiviral Properties and Promotes Cytolytic CD8 ⁺ T Cell Responses

The type‐I interferon family is well known for its critical role in innate immunity. It comprises several members, among which IFN‐α ₂ and IFN‐β are the most extensively studied, with important antiviral and immune‐modulatory functions. Recent findings linking autoantibodies against type‐I interferons to severe COVID‐19 suggest a potential role for IFN‐ω in combating SARS‐CoV‐2 infection. However, little is known about human IFN‐ω, as most research on this interferon has been conducted in feline models. Here, we demonstrate that human IFN‐ω is secreted at levels comparable to those of IFN‐α ₂ or IFN‐β upon stimulation with inflammatory agonists and triggers a robust antiviral response, inhibiting SARS‐CoV‐2 infection in vitr o . Moreover, IFN‐ω enhances the effector functions of antigen‐specific CD8 ⁺ T cells primed de novo from healthy donor cells, highlighting its capacity to promote strong cellular immunity. Our results position IFN‐ω as a key member of the type‐I interferon family, with promising potential for therapeutic and vaccine applications.