At a glance.
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Australia approved a single-dose chlamydia vaccine for koalas, showing vaccination can curb a real - and for koalas, deadly - epidemic in the wild.
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Human chlamydia is widespread and often symptomless, which fuels ongoing transmission and serious outcomes like infertility and ectopic pregnancy. Furthermore, chlamydia infection has been identified as a co-factor for increased cancer risk.
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The human pathogen differs from the koala strain, but the same prevention principle applies: match the right antigen (protein target) and the right delivery platform to the biological needs.
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Ziphius is aiming for protection leveraging their own self-amplifying mRNA-based platform designed to elicit the immune response required to fight human chlamydia.
Australia just demonstrated vaccination can control a chlamydia epidemic.
Australia has approved a chlamydia vaccine for koalas. That single decision shows something investors rarely get to see at this stage: population-level proof that vaccination can control a chlamydia outbreak in the real world.
How do vaccines work?
A vaccine gives the immune system a safe preview of a disease-causing pathogen, so it can learn to react quickly the next time. This causes the body to recognize the real invader when it is met and stimulates immune cells to remove the threat. Most importantly, vaccines create a memory of this lesson to make sure protection lasts.
What is in the koala vaccine?
The approved koala vaccine combines three harmless chlamydia proteins that teach the immune system what to look for without causing disease. They are formulated with an adjuvant that boosts the immune response to help make one injection sufficient in hard-to-recapture wildlife.
Veterinarians can now use the vaccine in wildlife hospitals, clinics, and the field. Some rollouts are starting under a minor-use permit while manufacturing scales up.
Chlamydia in humans is common, underdiagnosed, and preventable.
Human chlamydia is a potentially serious condition that can cause infertility and neonatal complications yet is often symptomless and is therefore spread unknowingly. Furthermore, chlamydia infection has been identified as a co-factor for increased cancer risk.
Screening and antibiotics help, yet incidence remains high, driven in part by stigma and lack of awareness. Prevention is the lever that changes lifetime risk, and the koala program shows the concept can work in a living population.
Koalas are not people, but the playbook holds.
Koalas face Chlamydia pecorum; people face Chlamydia trachomatis. We cannot copy the koala vaccine, but we can learn from the strategy: pick human-relevant antigens and deliver them in a way that drives the right immune response, so disease can be prevented. The koala program is not a one-off lab exercise; it is a national rollout with conservation agencies and regulators aligned, which gives early, real-world confidence to build on.
What other approaches show promise for human chlamydia?
mRNA vaccines notoriously shot to fame during the COVID-19 pandemic. They contain mRNA, a tiny set of instructions that teaches your cells to make a harmless “training” protein from the infection. In other words, the body creates its own ‘most-wanted poster’ for your immune system to practice on. This approach is great because it can be designed and manufactured at unprecedented speed.
The main limitation of first-generation mRNA vaccines is the short window of protection against the pathogen which means repeated administration at higher dosage is needed.
Self-amplifying RNA (saRNA) is a more dose-efficient approach.
Self-amplifying mRNA (saRNA) includes a small replicase that amplifies the message inside cells, giving stronger, longer-lasting training from much smaller doses. This lower dose is beneficial for cost, access, scale, and safety, particularly for large-scale programs.
The saRNA approach already has human precedent.
Ziphius is not the first to use this approach. An saRNA COVID-19 vaccine has regulatory approval in Japan. That de-risks the modality and means saRNA manufacturing playbooks already exist, which shortens the path from promising biology to scalable product. Ziphius is the first to apply this approach to human Chlamydia trachomatis.
Ziphius is developing an saRNA vaccine which shows promise for human chlamydia.
Ziphius has created an saRNA construct that carries the instructions for carefully chosen Chlamydia trachomatis proteins and packaged it in lipid nanoparticles (LNPs), which are tiny, engineered fat bubbles designed to protect the RNA and help it enter cells.
In non-human primates, validation tests with a SARS-CoV-2 model antigen encoded in the Ziphius saRNA platform generated a strong and lasting immune response with rapid, full clearance of the virus.
Furthermore, preclinical studies in a range of species have also generated a favorable safety profile. Together, these results give us confidence as we prepare for first-in-human trials.
What success could look like for investors.
A vaccine that protects young adults and future parents against a serious, underestimated disease, reduces the need for antibiotics, and becomes part of routine preventive care. A platform approach that can be applied to additional programs without starting from scratch. That’s the kind of investment your teens will be proud of.
A boat will turn heads for a summer. A vaccine can change the future of a generation.
Koalas proved vaccination can beat the threat of chlamydia. Ziphius is positioned to make that true for people.
Interested in learning more about our chlamydia program and platform roadmap? Feel free to get in touch.
Next in the series: the hidden link between chlamydia, HPV persistence, and cancer.
About the author: Chris Cardon.
Chris Cardon is the Founder and CEO of Ziphius. As a pharmacist-turned business builder, he is known for decisive leadership, disciplined capital allocation, and tight partnerships with clinicians and academics. He has 25+ years of turning cutting-edge biology into market-ready products and profitable companies.
He founded Mooss Pharma and exited in five years. He then founded and scaled Ecuphar across Europe before leading its 2017 reverse takeover of UK-listed Animalcare Group in a transaction recognized as AIM Transaction of the Year (AIM is the London Stock Exchange’s growth market) and awarded the Export Lion of Flanders.
At Ziphius, Chris brings public-market discipline and speed to a next-generation saRNA vaccine platform. Under his leadership, the team includes experts who have taken vaccines from bench to global launch, built EMA/FDA-standard manufacturing from scratch, executed €3B+ in licensing/partnering deals, and authored 250+ papers and 50+ patents reflecting the level of execution investors expect when science becomes product.
His philosophy is simple: build things your family can be proud of because they improve lives on a large scale.