Southern elephant seal pups were among the first to die when a deadly strain of avian influenza arrived in the Crozet Islands in 2024. But as the virus spread across the sub-Antarctic archipelago, a handful of penguin chicks had a potential advantage: They’d gotten a flu shot.
Disease ecologist Thierry Boulinier and his colleagues were poised to wrap up a small vaccine trial in young king penguins on the archipelago’s Possession Island when the virus arrived in October. A slew of H5N1 outbreaks that swept the globe in 2022, killing birds and mammals including bald eagles and red foxes, was a “clear motivating factor” in starting the trial, says Boulinier,