Professors Peter Timms and Ken Beagley from Queensland University of Technology's Institute of Health and Biomedical Innovation (IHBI) said the vaccinated koalas, which are at Brisbane's Lone Pine Koala Sanctuary, were mounting a good response to the vaccine.
"A good T-cell immune response is essential if the vaccine is to be effective," Professor Timms said.
"This initial trial will measure only the animals' immune response and will not involve any live chlamydial infections.
"If all goes well with this trial our future studies will evaluate the vaccine on sick and injured koalas brought in for care, relocated animals, and koalas in other sanctuaries.
"As many as 25-50 per cent of koalas coming into care in both Queensland and NSW are showing clinical signs of the disease and it seems to be getting worse."
The researchers have been working on developing a vaccine for the sexually transmitted disease chlamydia trachomatis in humans for many years.
"We've been able to develop the vaccine for koalas as a result of our studies on the development of human chlamydial vaccines done in the mouse model. We identified several novel vaccine proteins that we are trialling to protect koalas as well," Professor Beagley said.
He said chlamydia in koalas was a significant cause of infertility, urinary tract infections, and inflammation in the lining of the eye that often led to blindness.
"The number of koalas with chlamydia seems to be increasing and when combined with habitat destruction, chlamydial disease continues to be a major threat to koalas' survival," he said.
Professors Timms and Beagley said that despite the importance of developing a vaccine against chlamydia for koalas the team is struggling to raise enough funds to continue their work.
Source: Queensland University of Technology
Explore further: Food poisoning: New detection method for bacterial toxin