A chlamydia vaccine trial for Gunnedah shire's koalas has been pushed back to spring because of the COVID-19 pandemic.
The potentially game-changing trial was planned for autumn, but the federal government's social distancing rules have put the University of Sydney's project on hold.
It is a blow for the researchers, led by zoologist Dr Valentina Mella, because it is the second time it has been postponed. The trial was first planned for January but due to the high heat and drought, they called it off.
The vaccine has been developed by the University of Sunshine Coast's Professor Peter Timms and his team and will be administered to sick and well koalas to both combat and prevent the disease. The vaccinated animals will then be monitored over a three-year period.
Dr Mella is very disappointed because she was so keen to see if it would make a difference to the shire's declining koala population.
"We're hoping October but we really don't know," she said.
"For six months, we're not allowed to do anything. We can't even come and check on the koalas .. [but] we're not giving up on this. It looks really positive, the results from the lab stuff. We're really hoping it will work."
The outcome of the temperature study the university carried out in January has also been delayed.
"A lot of stuff hasn't been analysed. We think by October/November we'll be able to have everything. We've sort of stalled," Dr Mella said.
The only glimmer of good news is the recovery and release of two of the three koalas the team delivered into the care of Gunnedah wildlife carer Martine Moran during their January field trip.
"One had to be euthanised because it was way past the point of being able to be helped; all the koalas were in poor body condition. The other two ate like little piglets. The vets said they were eating like crazy, which shows how hungry they were," Dr Mella said.
The two male koalas went to Taronga Western Plains Zoo's wildlife hospital to be tested for chlamydia - one was positive and was treated.
They went back into Mrs Moran's care for a time and were nicknamed Pierre the Bear and Eddie before travelling back to Taronga for a final check-up.
The koalas were given a bill of clean health and were released back onto the property Dimberoy by farmer and koala water drinker designer Robert Frend on Wednesday.
"We're very happy about that because they were in very poor condition," Dr Mella said.