World-First Vaccine Approved to Combat Chlamydia in Koalas, Potentially Saving Thousands from Extinction
A groundbreaking vaccine designed to combat chlamydia in koalas has been given the green light, marking a significant advancement in the fight against this disease, which is a primary cause of mortality among these beloved marsupials.
Researchers at the University of the Sunshine Coast (USC) announced on Wednesday that they have developed a single-dose vaccine without the need for a booster. This innovative solution aims to stem the rapid and destructive spread of this disease, particularly in South East Queensland and New South Wales, where infection rates within populations can reach alarming levels of up to 70%.
Professor Peter Timms, a microbiology expert at USC who led the research team, stated, “Some individual colonies are teetering on the brink of local extinction every day. The high infection rates among koalas in these regions pose a significant threat to their survival.”
Chlamydia in koalas can lead to blindness, starvation due to an inability to locate food sources, infertility, and bladder inflammation resulting in blood passage. The disease can be transmitted through various means, including mating, infected discharges, at birth, and even by baby koalas consuming pap—a substance similar to feces produced by their mothers when infected.
Antibiotics have been employed to treat chlamydia in the past, but they are not always effective and do not prevent future infections. Additionally, antibiotics can cause gastrointestinal side effects that may impede koalas’ ability to digest eucalyptus leaves, their primary food source. In severe cases or where treatment has been delayed, euthanasia may become the only viable option.
The optimism surrounding the vaccine stems from its effectiveness in clinical trials involving hundreds of wild and captive koalas. The vaccine targets Chlamydia pecorum’s major outer membrane protein (MOMP), offering three levels of protection: reducing infection, preventing the progression to clinical disease, and, in certain cases, alleviating existing symptoms.
A study published last year by senior researcher Sam Phillips at USC revealed that the vaccine reduced chlamydia signs during a koala’s reproductive years and decreased mortality from the disease by 64%.
The vaccine has received approval for production and widespread use from the Australian Pesticides and Veterinary Medicines Authority (APVMA). The APVMA granted a permit authorizing the use of the vaccine in koalas in June, with the permit valid through June 2027.