By: Kloe Adams

Games Creator

The Australian Pesticides and Veterinary Medicines Authority (APVMA) approved the production and widespread use of a vaccine that prevents chlamydia in koalas. Found only in Australia, koalas are considered endangered in Queensland, New South Wales, and the Australian Capital Territory. Numerous threats endanger koalas’ lives, including disease, habitat loss, climate change, and road collisions. 

Koalas contract chlamydia through mating, infected discharges, and at birth. Baby koalas, also known as joeys, can catch chlamydia by eating their infected mother’s pap, a substance similar to feces. When contracted, koalas face an abundance of symptoms, including blindness, infertility, and bladder damage. As a result of blindness, koalas face difficulty locating trees to climb for food, ultimately leading to starvation. While veterinarians used antibiotics in the past to treat chlamydia, the antibiotics were not fully effective and did not prevent further infections. Additionally, antibiotics lead to gastrointestinal side effects that hinder the koalas’ ability to digest eucalyptus leaves, their main food source. Depending on the severity of the chlamydia and its progression, euthanasia may be the only option. 

Researchers at the University of Sunshine Coast (UniSC) in Australia have worked for the past ten years developing a single-dose vaccine that does not require a booster. Research leader, Professor Peter Timms, commented on their new vaccine: “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.” With APVMA’s recent approval, veterinarians can now use the vaccine in wildlife hospitals, veterinary clinics, and in the field to protect the nation’s most at-risk koalas. Certain individual colonies face a greater risk of extinction, particularly in South East Queensland and New South Wales, where infection rates within populations are often around 50 percent and, in extreme cases, can reach as high as 70 percent. 

The new vaccine is “based on Chlamydia pecorum’s major outer membrane protein (MOMP), and offers three levels of protection – reducing infection, preventing progression to clinical disease and, in some cases, reversing existing symptoms,” senior researcher at the UniSC, Sam Phillips, commented. In a study Phillips led last year, findings showed that the vaccine reduced signs of chlamydia during a koala’s breeding age and decreased death from the disease by 64 percent. Researchers and veterinarians hope to see continued positive results through June 2027, when the permit authorizing the use of the vaccine ends. 

(Sources: CNN, Los Angeles Times, NPR)