New Zealand is racing to protect its critically endangered birds, including the kākāpō, from deadly H5N1 avian influenza before migratory birds introduce the virus. With fewer than 250 kākāpō left, even a single outbreak could be catastrophic.
In a world-first trial, the Department of Conservation vaccinated 10 captive birds from five species with 500 or fewer individuals, using an H5N3 poultry vaccine. After two doses, four species developed strong antibody responses lasting at least six months, offering hope for protecting breeding populations in captivity and on offshore islands.
The next step is careful deployment planning before spring migration, as vaccinating wild populations at scale is logistically challenging. Australia and the US have explored similar programs, including emergency vaccination of California condors after H5 outbreaks.
Experts warn vaccines can lose effectiveness over time or drive viral evolution, but for species teetering on the brink of extinction, even partial protection is crucial.
“If we start too soon, immunity may fade. If too late, we might miss the crucial moment,” says DOC senior science adviser Kate McInnes.

