Canada is facing a potential disruption in its decline of COVID-19 cases with the emergence of a new family of subvariants known as the FLiRT variants. These genetic cousins, originating from the JN.1 Omicron subvariant that fueled a winter surge, are spreading nationwide, with one variant, KP.2, quickly gaining dominance. As of April 28, KP.2 accounted for 26.6 per cent of all COVID-19 cases in Canada, surpassing other JN.1 subvariants. The World Health Organization (WHO) stated that the KP.2 subvariant began circulating globally in January and is a descendant lineage of JN.1, the dominant strain worldwide. The emergence of KP.2 was first observed in Canada in February.
The FLiRT variants, including KP.2, KP.1, and KP.3, get their name from specific amino acid mutations in the spike protein of the virus. While these variants may be more adept at evading immunity, most individuals in Canada have either been infected with COVID-19, vaccinated, or both. This provides some level of protection, especially for healthy adults and children. However, seniors and immunocompromised individuals remain at risk. The majority of individuals have likely built some immunity, reducing the severity of potential infections caused by the FLiRT variants.
Symptoms of the FLiRT variants are similar to those of the Omicron lineage. While data is still fresh, preliminary findings suggest that these variants may be less infectious than their predecessors. Vaccines currently available in Canada target the XBB 1.5 Omicron subvariant, but experts believe they should still provide some level of protection against the FLiRT variants. Young, healthy individuals who received their COVID-19 vaccine in the autumn likely won’t need another booster until fall 2024. However, seniors and immunocompromised individuals are advised to get the spring booster.
The National Advisory Committee on Immunization (NACI) has released guidelines anticipating another surge in the fall and winter months, with an updated vaccine potentially available starting in the fall of 2024. The WHO’s Technical Advisory Group on COVID-19 Vaccine Composition has recommended including the JN.1 variant in future vaccine formulations. This could be a challenge, as the virus is constantly mutating, similar to the challenge of staying ahead of the influenza virus. The evolving nature of the virus suggests the need for ongoing monitoring and adjustments to vaccination strategies to effectively combat the changing landscape of COVID-19.
Experts express concerns about the potential for an uptick in COVID-19 cases due to the FLiRT variants, particularly the dominant KP.2 subvariant. While the severity of infections may be lower, the possibility of reinfections and breakthrough cases remains a concern. As the virus continues to evolve, it is crucial to stay vigilant and adapt public health measures and vaccination strategies accordingly. The emergence of new variants underscores the need for ongoing research, surveillance, and international collaboration to effectively control the spread of COVID-19 and protect public health.
