Serious problem: Chlamydia causes infertility, urinary tract infections and blindness in koalas, and is increasingly common. In stressed populations up to 80 per cent of koalas are infected.
Credit: Wikimedia
SYDNEY: A vaccine has been successfully developed to protect koalas from the scourge of chlamydia, a disease that is threatening populations across Australia.
Eighteen healthy koalas at the Lone Pine Koala Sanctuary in Brisbane have been treated with the experimental vaccine and are showing a good immune response, researchers say.
Chlamydia causes infertility, urinary tract infections and blindness in koalas, and is increasingly common. In stressed populations up to 80 per cent of koalas are infected.
High levels of infection
"As many as 25 to 50 per cent of [all] koalas coming into care in both Queensland and New South Wales are showing clinical signs of the disease and it seems to be getting worse," said Peter Timms, one of the researchers behind the project at the Queensland University of Technology (QUT) in Brisbane.
This is the first time a vaccine has been developed for chlamydia in koalas, said Ken Beagley, a QUT immunologist.
The pair have also been working on a vaccine for human chlamydia. The various strains are very similar, said Beagley, so their team identified a number of proteins that are common to all strains and designed a 'sub-unit' vaccine for use in koalas.
Sub-unit vaccines use only a few proteins from the bacterium rather than a whole organism, so there is no chance of accidentally infecting a koala with chlamydia from the vaccine. These proteins, which are specific to the bacterium, act as antigens to train the immune system to recognise the threat.
"Very important development"
Koalas will not subsequently be exposed to chlamydia to test their resistance, Beagley said; instead, their immune response to the vaccine will be monitored over the course of a year.
Veterinary scientist Mark Krockenberger, from the University of Sydney, said it was very encouraging work: "Chlamydiosis certainly is a very significant disease of koalas in most of their range … [This trial is] only the first step in the process but is a very important development."
Krockenberger believes that, with its strong background in chlamydia research and immunology, the QUT team has the best possible chance of making the vaccine succeed. However, Beagly said they are struggling to raise enough funds to continue their work.
