A regulator has approved a world-first vaccine to protect koalas from chlamydia infections, which are causing infertility and death in the iconic native species that is listed as endangered in parts of Australia.
The single-dose vaccine was developed by the University of the Sunshine Coast in Queensland state after more than a decade of research led by professor of microbiology Peter Timms.
The research showed the vaccine reduced the likelihood of koalas developing symptoms of chlamydia during breeding age and decreased mortality from the disease in wild populations by at least 65%.
The recent approval by Australia’s veterinary medicine regulator means the vaccine can now be used in wildlife hospitals, veterinary clinics and in the field to protect the nation’s most at-risk koalas, Timms said on Wednesday.
“We knew a single-dose vaccine — with no need for a booster — was the answer to reducing the rapid, devastating spread of this disease, which accounts for as much as half of koala deaths across all wild populations in Australia,” Timms said in a statement.
“Some individual colonies are edging closer to local extinction every day, particularly in southeast Queensland and New South Wales, where infection rates within populations are often around 50% and in some cases can reach as high as 70%,” Timms added.
Deborah Tabart, chair of the conservation charity Australian Koala Foundation, said resources being spent on vaccinating koalas should be redirected at saving koala habitat.
“At the risk of sounding flippant, how can anyone be so delusional as to think that you can vaccinate 100,000 animals? It’s just ridiculous,” Tabart said on Friday.
Tabart’s foundation estimates there are fewer than 100,000 koalas in the wild. The government-backed National Koala Monitoring Program estimated last year there were between 224,000 and 524,000 koalas.
“I accept that chlamydia is an issue for koalas, but I also want people to understand that they’re sick because they haven’t got any habitat,” Tabart said.
The Queensland Conservation Council, an umbrella organization for more than 50 environmental groups across the state, welcomed the vaccine. But the council’s director, Dave Copeman, echoed Tabart’s focus on preserving koala habitat.
“It’s really good news. Chlamydia is one of the key stresses that has been putting pressure on koala populations,” Copeman said.
“Koalas were at risk before chlamydia outbreaks, and they will remain at risk even if we manage chlamydia perfectly, because we keep on destroying their habitat,” he added.
Koalas are listed as endangered species in the states of Queensland and New South Wales and in the Australian Capital Territory, with habitat loss due to wildfires and urban expansion as the major threats. Chlamydia can cause urinary tract infections, infertility, blindness and death.
Treatment with antibiotics can disrupt an infected koala’s ability to digest eucalyptus leaves — its sole food source — leading to starvation, the university said in a statement.
The research has been supported by the federal, New South Wales and Queensland governments.
Federal Environment Minister Murray Watt said his government had contributed to the vaccine’s development through a 76 million Australian dollar ($50 million) Saving Koalas Fund.
“We know that koalas need help to fight diseases like chlamydia. It’s a widespread threat impacting their reproductive health and causing infertility,” Watt said in a statement.
Koalas are iconic Australian marsupials, like wombats and kangaroos. They spend most of their time eating and sleeping in eucalyptus trees, and their paws have two opposing thumbs to help them grasp and climb up tree trunks.
Australia’s wild koala populations have declined steeply in the past two decades.
Facing compounded threats from disease, habitat loss, climate change and road collisions, koalas could become extinct by 2050, according to a 2020 assessment from the New South Wales government.
Published – September 14, 2025 02:45 pm IST
