Key Points
- A new COVID-19 variant, which experts say could be more transmissible, is circulating in Australia.
- They say the new variant doesn’t appear to cause more severe symptoms than previous, similar variants.
- And Australia could be nearing a winter peak in COVID-19 cases, an expert says.
A new variant, LB.1, is circulating in Australia — and experts warn it could spread faster than previous variants.
A Department of Health spokesperson said there had been confirmed cases of LB.1 in Australia. However, the JN.1 variant (and related KP.2 and KP.3 variants) remained responsible for the majority of new infections over the period 7 May to 11 June.
FLiRT and , , attracted attention earlier this year. LB.1 is similar, but different. Epidemiologists are referring to it as D-FLiRT because of changes to spike proteins (the part of the virus that allows it to invade human cells)
“Although LB.1 is almost certainly more transmissible than KP.2, it doesn’t appear to be outperforming KP.3 and its descendants,” Professor Adrian Esterman, chair of biostatistics and epidemiology at the University of South Australia, told SBS News.
“All of these descendants of JN.1 appear to have similar severity. Oral antivirals will still work against LB.1, and our current vaccines will still give some (but reduced) cross-immunity.”
Experts say the new variant doesn’t appear to cause more severe symptoms than previous, similar variants. Source: Getty / Westend61/Getty Images/Westend61
In the United States, KP.2 and KP.3 variants made up the majority of new cases at 37 per cent and 24 per cent respectively over the two weeks to 6 July, according to the Centers for Disease Control and Prevention (CDC) Nowcast estimates. LB.1 was responsible for an estimated 15 per cent of infections, with other variants making up the remainder.
Why is LB.1 being referred to as D-FLiRT?
The acronym D-FLiRT comes from the technical names of the different variants’ mutations, one of which includes the letters F and L and another of which includes the letters R and T.
The D refers to a “missing piece,” said Paul Griffin, an infectious disease physician and clinical microbiologist at the University of Queensland.
“It’s got an extra deletion on the spike protein and that additional change means that our recognition by our immune system is a bit less, and therefore gives the variant an opportunity to spread a bit more easily,” he said.
“Whenever the spike protein changes, it means that our protection from past infection or vaccination is reduced and therefore they become a bit more transmissible,” he said.
Has Australia reached a peak in COVID-19 cases?
Griffin said Australia appeared to be nearing a peak in coronavirus cases this winter. But he added that it’s hard to tell how future cases will track and whether the new variant will cause a new wave of infections.
“We had a large wave of COVID activity and that does seem to be stalling, but there is still quite a lot (of COVID) at the moment,” he said.
“It’s problematic because it’s overlapping significantly with our flu season. And we’ve also still got other things like mycoplasma and whooping cough going around, so it does mean there’s lots of people with respiratory infections at the moment.”
D-FLiRT was first detected in the US in March, and the CDC says there are no signs so far that the new LB.1 variant is causing more severe disease in COVID-19 patients.
FLiRT, FLUQE and D-FLiRT have descended from and became the dominant form of COVID-19 in Australia.
The most recent COVID-19 surveillance reports of Australia’s two most populous states — NSW and Victoria — published over the past week found COVID-19 cases appeared to be declining.
COVID-19 cases admitted to hospitals also appear to be declining, according to Australia’s National Notifiable Diseases Surveillance System (NNDSS). The seven-day average on 9 July was 53 cases, down from 107 a week earlier.
However, there can be delays in reporting to the NNDSS, and it does not include data from NSW hospitals.
