Australia approves first vaccine to save koalas from chlamydia

ENVIRONMENT – BIODIVERSITY

15 SEPTEMBER 2025

• The world’s first koala chlamydia vaccine has been approved by Australia’s veterinary medicine regulator.
• It was developed by the University of the Sunshine Coast, Queensland, after over a decade of research led by Prof. Peter Timms.

Significance

• Koalas are listed as endangered in Queensland, New South Wales, and the Australian Capital Territory.
• Chlamydia accounts for up to 50% of koala deaths in the wild.
• Infection rates: often 50% in wild populations, and up to 70% in some colonies.
• Antibiotic treatment is problematic because it disrupts digestion of eucalyptus leaves (koalas’ only food), leading to starvation.

Effectiveness

• The vaccine reduces the likelihood of koalas developing chlamydia symptoms during breeding age.
• It decreases mortality in wild populations by at least 65%.