FLiRT-ing with a new COVID-19 wave

The 'FLiRT' sublineages, including KP.2 and KP.3, stem from JN.1, which dominated infections early this year.

KP.2 made up around 50 per cent of COVID-19 infections in NSW up until May 4, according to NSW Health.

While the Department of Health, Victoria found KP.3 and other JN.1 variants were in wastewater in "increasing abundance" in their May 17 report.

The World Health Organisation has classified these subvariants as "circulating variants under monitoring".

The FLiRT name derives from the technical names of the mutations in the genetic codes of the variants.

Deakin University's chair of epidemiology, Catherine Bennett said these JN.1 sub-variants have been in Australia since February but were likely to increase into winter.

"This looks like the early days of our winter pandemic, it will be driven by these K variants, the FLiRTs," she said.

"FliRT variants take up about half of the variants circulating, and if they take off they might push JN.1 into the background."

Professor Bennett said the severity of the variants was similar to its parent strain but that disease-impact depended on the individual.

"Our immune memory isn't as fitted to this new variant so it can make us a bit more vulnerable."

Professor Bennett said while repeat waves of COVID-19 were expected, there would be larger gaps between waves.

"With each wave we have seen fewer people unwell with the virus and fewer deaths associated with each wave," she said.

Professor Bennett said people vulnerable to severe disease or those who have managed to avoid infection should consider if they are eligible again for a booster vaccine.

"We are seeing a rise in infections, by June we may well have quite a few cases, and if you get the vaccinations now it prepares you," she said.

Professor Bennett warned that a negative rapid antigen test did not necessarily mean someone did not have COVID-19 as the peak in viral load is more likely two or three days after symptoms.

If the flu season coincided with the COVID-19 season, Professor Bennett said Australians should consider masking on public transport and not socialising when symptomatic.

"It doesn't matter whether it's a cold, flu, COVID, or RSV, just think about staying home, resting and getting well rather than socialising and spreading the virus," she said.