Evidence of Exposure to Highly Pathogenic Avian Influenza H5 Viruses in East Greenland Polar Bears

Abstract

We detected influenza A virus antibodies in plasma collected from East Greenland polar bears during subsistence hunts in 2024 (3/14 [21%]) and 2025 (6/14 [43%]). Four bears from 2025 had antibodies for the globally emerging highly pathogenic avian influenza virus H5 clade 2.3.4.4b, consistent with survival after exposure.

Kayla J. Buhler, Charlene Ranadheera, Nathalie Bastien, Marcy Zirino, Emily Jenkins, Morten Tryland, Rune Dietz, Jens Søndergaard, and Christian Sonne