A rSIV.F/HN vector was generated to express T1-3B anti-influenza nAb under the transcriptional control of the hCEF promoter, which is known to be active in the human lung.6 For simplicity, the T1-3B IgG1 heavy and light-chain cDNAs were fused into a single open reading frame via a furin cleavage site and 2A self-processing peptide.2 Intranasal delivery of this vector (rSIV.F/HN.hCEF.T13B) at doses of 6e5, 6e6 or 5e7 transducing units (TU) resulted in T1-3B in the serum and epithelial lining fluid (ELF, n=6–8). This evidence concerns the gene FURIN and influenza.