A promising new COVID-19 vaccine candidate developed by researchers at the Centenary Institute and the University of Sydney has shown strong potential to protect against both current and emerging coronavirus variants. By targeting features shared by a range of coronaviruses, the vaccine is designed to offer broader and longer-lasting protection as the virus continues to evolve.
The development comes as Australia faces continued COVID-19 circulation during winter, with new Omicron subvariants such as XBB.1.5 contributing to infections and hospitalisations. To date, there have been over 115,000 COVID-19 cases reported to the Australian Government’s National Notifiable Diseases Surveillance System for 2025.
Published in the scientific journal npj Vaccines, the new study shows that the vaccine candidate, named CoVEXS5, protected mice from multiple coronaviruses, including the highly immune-evasive Omicron XBB.1.5 variant and SARS-CoV-1, a relative of SARS-CoV-2 that was responsible for the 2002–2004 SARS outbreak.
In laboratory tests, CoVEXS5 reduced virus levels in the lungs of infected mice by approximately 99.9% compared to unvaccinated controls, demonstrating a dramatic protective effect.
