Health experts are warning Australians to brace for a triple threat this winter, as COVID-19, influenza, and RSV continue to spread rapidly. The strongest protection, they say, is timely vaccination—ideally before the end of May.

“We’re already seeing an early wave of highly infectious respiratory illnesses,” said Professor Paul Griffin on Wednesday. “When one person in a household gets sick, the virus can spread to everyone within days. Early detection is key to managing outbreaks and protecting vulnerable groups.”

As of May 22, more than 80,000 flu cases have been confirmed across Australia—a more than 50% increase from the same time last year. Influenza, typically caused by type A or B viruses, is a highly contagious respiratory infection with several subtypes and strains.

COVID-19 cases are also expected to surge in the coming months, driven largely by a highly transmissible Omicron subvariant known as LP.8.1. This strain was responsible for 60% of COVID cases in the UK by March and has been linked to significant outbreaks overseas since late 2024. While not more severe than previous strains, it appears to spread more easily.