Canada’s respite from COVID-19 cases faces potential disruption with the emergence of a new group of subvariants, affectionately termed the ‘FLiRT’ variants.
These genetic relatives, stemming from JN.1, the Omicron subvariant that drove the winter surge, are now spreading nationwide, with one variant, KP.2, swiftly gaining prominence in Canada.
KP.2, the dominant subvariant of the JN.1 strain, as explained by Gerald Evans, an infectious disease specialist at Queen’s University in Kingston, Ont., accounted for 26.6 per cent of all COVID-19 cases in Canada as of April 28, surpassing other JN.1 subvariants.
These subvariants, including KP.1 and KP.3, collectively form what is referred to as the FLiRT variants.
Evans clarified the origins of the FLiRT designation, stating that it carries scientific significance. Named for specific mutations in amino acids, FLiRT stands for phenylalanine (F) replacing leucine (L) and arginine (R) replaced by threonine (T), with the addition of “I” to form a pronounceable term.
The World Health Organization (WHO) reported that the KP.2 subvariant began circulating globally in January, originating from JN.1.
In Canada, the appearance of KP.2 was initially noted in February. Evans explained that the name “KP.2” denotes the accumulation of mutations, necessitating a new prefix. Thus, JN.1 evolved into KP.2, signifying the ongoing evolution of the virus rather than a distinct variant.
While COVID-19 transmission levels remain relatively low across Canada, Dr. Isaac Bogoch, an infectious diseases specialist, suggested that the latest mutation may possess increased immune evasion capabilities, potentially leading to a resurgence in cases.
Syra Madad, DHSc, MSc, emphasized that current data hasn’t demonstrated increased severity of illness associated with the FLiRT variants. However, ongoing research will provide further insights into their impact on public health.