Pregnant Koala Inspires Hope After Species Saving Vaccine

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Australian researchers have developed a vaccine for koalas to combat an extensive outbreak of sexually transmitted diseases in the species.

Koala’s, which have been hit hard by changing climatic conditions, bushfires, and land clearing, are under pressure from an ongoing chlamydia outbreak that is causing the marsupials to become infertile and further pushing the species towards potential extinction.

The senior veterinarian at the Currumbin Wildlife Hospital, Dr. Michael Pyne, said he had witnessed a significant growth in the number of koalas admitted to his hospital over his career.

“I first started working at the hospital 20 years ago; it was unusual to see a koala admitted. We probably only saw about two or three per year,” Pyne said. “Fast-forward 20 years, and we are admitting up to 500 koalas annually. It’s heartbreaking to see the problems our koalas are facing.”

Of the 500 koalas admitted annually, 60 percent are sick or dying from chlamydia, while many of the other 40 percent were becoming sick from subclinical chlamydia.

Subclinical chlamydia is where koalas are in the initial stages of developing a full-blown bacterial infection.

“Without preventative measures, koalas are on track to become extinct in large areas of Eastern Australia. If this vaccine is effective, then we have hope to prevent koalas getting sick in the first place.”

A koala chews on gum leaves at the Wild Life Park in Sydney, Australia, on April 23, 2012. William West/AFP/Getty Images

The vaccine trial aims to track and monitor 30 koalas in the Gold Coast’s Elanora area for three years, recapturing the koalas every six months to check on their reproductive ability and chlamydia immunity.

So far, the vaccine trial has indicated that the treatment is effective, with test subject Cassidy the koala becoming pregnant and testing negative to the bacteria 12 months after the trial’s launch.

Pyne said that Cassidy’s pregnancy was promising as she was living in an area where there are numerous cases of chlamydia in the local koala population.

“It’s encouraging that Cassidy is pregnant and negative to chlamydia, not only for the research trial but for the entire koala species,” Pyne told AAP.

Additionally, of the 12 koalas that participated in the trial, the six koalas that have been recaptured are healthy and have tested negative for the bacteria.

“It’s still very early stages and too early to say if the vaccine will be a long-term solution,” Pyne said. “However, Cassidy is making us hopeful.”

“We’re not going to suddenly eliminate it, but vaccinating is part of ongoing management to save koalas,” he said. “If we can vaccinate a certain percentage of Koalas, our model shows we should be able to get the numbers back up, so they’re off the vulnerable species list. Because the next point on that list is endangered, and we really don’t want that.”.

A koala and her joey climb a tree. Illustration - jeep2499/Shutterstock

However, there is a snag in the conservation project; vaccinating the koala population is currently very expensive.

“To be capturing a koala from the wild, vaccinating, releasing that koala back to the wild, tracking it and recapturing it to assess how well the vaccine’s working, we’re looking at around about $25,000 a year per koala,” Pyne said.

On average, the 500 koalas that are brought in annually to the animal hospital for chlamydia treatment typically costs around $7000 (approx. US$5000) unless there are complications from the antibiotic treatment, in which case the cost is much higher.

Pyne said that the price of the vaccine would go down after the trial and, if the vaccine is effective and the number of koalas immune to chlamydia rises, the need for the vaccinations and the chlamydia treatment will be lessened significantly.

Prof. Kenneth Beagley from the Queensland University of Technology, who administered the chlamydia vaccine to 145 koalas whilst working with the hospital, hopes the trial will boost the koala population.

“It’s fantastic news that the vaccine has protected Cassidy and that she is now pregnant with a joey despite living in a population with a very high prevalence of chlamydia,” Beagley told AAP.

“I do have cautious optimism for the future of the species. Hopefully, we can repeat this and see the koala population increase over time.”