Australia Approves First Vaccine to Protect Koalas from Chlamydia

Australia has authorized the first vaccine designed to protect koalas from chlamydia, a disease significantly impacting their population. This single-dose vaccine is approved for use in wildlife hospitals, veterinary clinics, and in the field. The development of this vaccine was a decade-long endeavor by researchers.

The koala population in Australia is estimated to be between 224,000 and 524,000, according to the country's national science agency. The World Wide Fund for Nature reports that the koala population has decreased by half in the last two decades. In certain regions, like Queensland, New South Wales, and the Australian Capital Territory, koalas are listed as endangered.

Chlamydia, a sexually transmitted infection also found in humans, is a major threat to koalas, contributing to their vulnerability alongside habitat loss, climate change, and bushfires. The infection can lead to infertility and blindness. It is common for a significant portion of a koala population to be infected, with rates potentially reaching as high as 70%.

The vaccine has been shown to reduce the likelihood of koalas developing chlamydia symptoms during their breeding years and to decrease mortality from the disease in wild populations by at least 65%. The vaccine underwent testing on over 500 koalas in eight trials before its approval.

The vaccine provides multiple levels of protection, including reducing infection, preventing the progression to clinical disease, and, in some cases, reversing existing symptoms. Previously, the only treatment available for infected koalas was antibiotics, which could cause digestive issues, leading to starvation and death.