Koalas in SEQ suffer badly from chlamydia infections, which cause blindness and infertility and are a major contributor to population decline and local extinctions. Koalas have been listed as an endangered species in 2022. The Reproductive Infection and Immunity Research Group at Centre for Immunology and Infection Control at QUT lead by Professor Ken Beagley have developed 2 chlamydial vaccines for koalas and are working with local wildlife hospitals, sanctuaries and veterinarians to evaluate these vaccines in both wild and captive koala populations.
Koala project 1 with Currumbin: Vaccination of wild koalas at Eleanora
The Eleanora population is a geographically isolated population on the Gold Coast with a high incidence (70-80%) of chlamydial disease, as determined by City of the Gold Coast council (CoGC) survey. Population numbers are decreasing. Working with Dr Michael Pyne at the Currumbin Wildlife Hospital, we aim to capture 10% of healthy young koalas every year for 5 years. Animals are captured by dedicated capture crews. They are given a complete health check including being tested for Chlamydia and treated if positive. Chlamydia-free and treated animals then receive 2 doses of a vaccine, 30 days apart. Between the first and second vaccinations animals are housed at CWH or a dedicated housing facility in Pottsville, NSW. After the second vaccine animals are collared and released as close as possible to the capture site. The solar-powered transmitters on the collars allow for VHF and GPS monitoring and tracking of animals. Animals are recaptured at 3, 6 and 12 months post-vaccination. At each capture animals are given a health check, tested for Chlamydia and the females checked for pouch young. At the end of 5 years the CoGC will carry out another survey to determine the incidence of chlamydial disease in the vaccinated and control populations. We hope to see a decrease in population incidence of chlamydial disease and an increase in healthy koala numbers.
Progress to date:
Number of animals captured/vaccinated/released 23
13 recaptured for 3-month check
7 recaptured for 6-month check
3 recaptured for 12-month check
ALL HAVE BEEN CHLAMYDIA-FREE (100%)
Number of females with joeys (9)
Koala project 2 with Currumbin: Comparison of a 1 and 2-shot vaccine in captive-bred koalas
Most work done to date is with our 2-shot vaccine, requiring a primary vaccination and a booster 30 days later. Experience with this vaccine suggests that immunity lasts up to 7-8 years. The one downside of this vaccine is that animals must be held in captivity for 30 days or released and recaptured for the booster. We have also developed a second vaccine, which requires only one primary vaccination. Preliminary data from this vaccine suggests the immunity does not last as long as the immunity generated by the 2-shot vaccine. We are currently comparing the immunity elicited by each vaccine in captive koalas bred at Currumbin. To date 4 animals have been vaccinated with each vaccine. Each group will eventually contain 20 animals.
Separately, we are also vaccinating all koalas that come to the Currumbin Wildlife hospital and are released back into the wild (up to 400 a year)