As COVID-19 cases rise once again, it’s important to stay informed about the new FLiRT variants. After more than four years of living with COVID-19, one thing is clear: the virus is here to stay.
Since the emergence of the original Wuhan variant, we’ve seen the virus evolve into multiple strains, including Delta and Omicron. Each new variant has driven waves of infection and challenged our understanding of the virus.
Now, a new group of variants, known as the “FLiRT” variants, is contributing to the latest surge in COVID-19 cases in Australia and other parts of the world. But what exactly are these variants, and should we be worried?
A Descendant of Omicron
The FLiRT variants are subvariants of JN.1, which comes from the Omicron lineage. JN.1 was first detected in August 2023 and was declared a variant of interest by the World Health Organization in December 2023. By early 2024, it had become the dominant variant in Australia and many other countries, driving significant waves of infection.
Scientists have been working diligently to understand the impact of these new variants, including sequencing their genes and assessing their transmissibility, infection potential, and disease severity. In late 2023, subvariants of JN.1 were detected in U.S. wastewater. These subvariants, including KP.1.1, KP.2, and KP.3, have since spread globally.
Why the Name FLiRT?
The name FLiRT comes from specific mutations in the virus’s spike protein: F456L, V1104L, and R346T. The spike protein is crucial for the virus to attach to our cells, and these mutations affect how the virus binds to host cells and how well our immune system can recognize and neutralize it.
Characteristics of FLiRT Variants
The mutations found in the spike protein of the FLiRT variants have two main implications. First, they may help the virus evade antibodies, making it harder for the immune system to recognize and fight it. Second, these mutations might enhance the virus’s ability to bind to host cells, potentially increasing its transmissibility.
There are early indications that the FLiRT variants could be more transmissible and better at evading immunity from previous infections and vaccinations compared to the original JN.1 variant. However, this research is still in its early stages and has not yet been peer-reviewed.
On a positive note, there is no evidence so far that the FLiRT variants cause more severe disease than previous variants. Nonetheless, catching a FLiRT-driven COVID infection is not without risk.
Current Situation and Future Outlook
In the United States, FLiRT variants have surpassed the original JN.1 variant, now accounting for the majority of cases. In Australia, although FLiRT subvariants have been detected more recently, they are quickly becoming more prevalent. For example, mid-May data from NSW Health showed an increase in the proportion of KP.2 and KP.3 samples.
As Australia heads into winter, respiratory viruses, including COVID-19, are expected to circulate more widely, leading to a rise in case numbers. The increased “fitness” of the FLiRT subvariants means they may soon become the dominant strains.
Protecting Yourself Against FLiRT Variants
Since FLiRT variants are descendants of Omicron, the current booster available in Australia, targeting Omicron XBB.1.5, should offer substantial protection. While it may not completely prevent infection, COVID-19 vaccines continue to provide strong protection against severe disease. If you’re eligible, getting a booster is a good step to protect yourself this winter.
As SARS-CoV-2 becomes an endemic virus, it will continue to mutate slightly to survive and circulate. The FLiRT subvariants are just another example of this ongoing evolution. While there’s no significant cause for concern about these variants specifically, the rise in COVID-19 cases remains a reality. Vulnerable individuals, such as those with compromised immune systems, are still at greater risk and should take necessary precautions.
