Since its detection in August 2023, the JN.1 variant of COVID has rapidly spread and become dominant in Australia and around the world, leading to a surge in cases not seen in many jurisdictions for at least the past year. The World Health Organization (WHO) classified JN.1 as a "variant of interest" in December 2023 and emphasized the continuing global health threat posed by COVID, with potential long-term health consequences.

JN.1 is significant for several reasons. Firstly, as a pathogen, it differs significantly from previous variants of SARS-CoV-2, swiftly replacing other circulating strains such as omicron XBB. This unique characteristic has implications for disease severity and transmission. Previously, variants of the virus have had a similar appearance to their predecessors, only accumulating a few mutations at a time to gain an advantage. However, JN.1 emerged seemingly out of the blue, displaying markedly different characteristics.

The emergence of JN.1 has raised questions about whether the WHO will designate it as the next "variant of concern" and assign it a Greek letter. It marks a new phase of the pandemic, with its distinct properties and the wave of new infections it has caused.

The origin of JN.1 can be traced back to its parent lineage BA.2.86, which appeared around mid-2023. BA.2.86 evolved from a sub-variant of omicron known as BA.2, which emerged in 2022. The virus silently accumulates mutations in chronically infected individuals, helping it evade immunity and survive. In the case of BA.2.86, more than 30 mutations in its spike protein, the part of the virus that attaches to human cells, have been identified.

The rapid global spread of JN.1 has set the stage for major viral evolution, as SARS-CoV-2 continues to undergo a high rate of mutation. JN.1 itself is already mutating and evolving at a rapid pace.

In laboratory studies, BA.2.86 and JN.1 have exhibited unique behavior in two key areas. Firstly, the virus evades immunity through the accumulation of mutations in its spike protein, hindering the ability of antibodies to bind to the virus and prevent infection. Secondly, the way JN.1 enters and replicates in human cells differs from previous variants. Research findings have shown conflicting results, with some studies suggesting similarities to the delta variant, while others align it more closely with omicron lineages. Further research is needed to understand the implications for disease severity and transmission.

Despite the unique characteristics of JN.1, evidence suggests that updated monovalent vaccines, tests, and treatments remain effective against it. However, JN.1 has a greater advantage in terms of global transmission, leading to an increased number of infections and potentially more severe illness and deaths.

The long-term trajectory of JN.1 and its potential to become the "next common cold" are still uncertain. The emergence of JN.1 emphasizes the continuous nature of the COVID epidemic, and calls for a reevaluation of the risks associated with recurring waves of infection. Global surveillance and intensified research are crucial for better pandemic preparedness and response.

It is essential to address the concerning lack of representation of low- and middle-income countries in global surveillance efforts, as this could present a blind spot in our understanding of emerging threats. Through collective efforts and a focus on research, we can navigate the ongoing COVID pandemic more effectively and ensure better preparedness for future challenges.