RAG2 and viral infectious disease: The nasal tissue, trachea and lungs were taken for tissue imaging, and only the nasal tissue and lungs of the mice in the control group (mock-treated with PBS) had obvious fluorescence signals (Figure 5E,F), while the corresponding organs from the mice administered with 1 or 5 mg/kg of the antibody showed no light signals, indicating that even a lower dose of the antibody could effectively inhibit viral infection and replication in Rag2−/− mice and the humanized monoclonal antibody had strong antiviral activity.