This koala was first to be vaccinated against chlamydia in new trial

Shano the Koala receives a vaccine against Chlamydia Terry Walsh at the University of the Sunshine Coast
In Queensland, Australia, a large clinical trial is underway to test a vaccine that protects koalas from chlamydia.

Australia's koalas have been hit hard by a chlamydia outbreak. Approximately 100 percent of certain populations are positive for the sexually transmitted disease. Rapid spread of the disease is believed to be a key factor in falling koala populations.

Peter Timms, University of the Sunshine Coast, Queensland, and his collaborators spent over a decade creating a vaccine that would protect koalas from the disease. This can cause painful urinary tract infections and loss of bladder control.

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The vaccine exposes the koalas and their immune system to small pieces of the Chlamydiapecorum bacterium, which can infect them. If they are infected, this vaccine will train the immune system to recognize and attack the pathogen.

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Eight studies have shown that vaccines protect koalas against catching chlamydia, and that they can reduce the severity of symptoms in infected animals.

The vaccine will be administered as a single injection to 200 Koalas at Australia Zoo Wildlife Hospital, Beerwah, Queensland. This is the largest ever trial. Shano, a koala from Shano, received the first jab on 15 October (pictured).

Timms and his associates will evaluate how many of the 200 vaccinated Koalas have chlamydia symptoms in the next 12 month to determine the effectiveness of vaccines. This is compared to 200 unvaccinated Koalas.

Timms believes that the vaccine could be approved for widespread distribution and help to restore koala populations that may have been threatened by extinction. His team already discovered that the vaccine combined with other veterinary treatment was effective in reverseing declining numbers of koalas in a region of south-east Queensland.

Timms suggests that similar principles could be used to create a vaccine against human chlamydia. This is caused by the bacterium Chlamydia trachomatis. He says that the human chlamydia vaccine industry will closely monitor this trial.