Comparative Distribution of α2,3- and α2,6-Linked Sialic Acid Receptors and Influenza A(H5N1) Virus Binding in Sheep, Goats, and Alpacas

A representative clade 2.3.4.4b H5N1 influenza A virus binds effectively to respiratory and non-respiratory tissues in sheep, goats, and alpacas, with strongest binding in sheep.

• Why it matters: H5N1’s expanding host range and new positives in minor livestock raise concerns about overlooked species’ susceptibility and influenza tissue tropism relevant to zoonotic risk.
• What they did: The study mapped α2,3 and α2,6 sialic acid receptors in respiratory and non-respiratory tissues using Maackia amurensis and Sambucus nigra lectins, then tested recombinant H5N1 viruses for tissue-specific binding.
• The result: Binding patterns were similar across clade 2.3.4.4b variants and a Gs/Gd precursor, and H1N1 and H3N2 also bound respiratory tissues of sheep and goats.