New Zealand is racing to protect its critically endangered birds, including the kākāpō, from H5 avian influenza before the spring migration brings the virus to its shores. With fewer than 250 kākāpō left, even a single outbreak could be catastrophic.
A world-first trial by the Department of Conservation vaccinated 10 captive birds from five species with the H5N3 poultry vaccine. After two doses a month apart, four species developed strong antibodies lasting at least six months, offering hope for safeguarding breeding populations in captivity and on offshore islands.
The next challenge is creating a strategic rollout ahead of migratory birds’ arrival. Vaccinating wild populations is logistically difficult and stressful, so authorities focus on captive and managed populations, while improving overall habitat and resilience.
Similar efforts abroad include the US vaccination of California condors after an H5 outbreak killed 21 birds in 2023. Scientists caution that vaccines may lose effectiveness over time or drive viral evolution, but the consensus is that vaccinated birds fare better than unvaccinated ones.
“If we start too soon, immunity may fade. If too late, we might miss the crucial moment,” says DOC adviser Kate McInnes.
