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JN.1, a new variant of COVID-19 detected in August 2023, has spread rapidly around the world, showing significant evolutionary changes from previous strains. This development requires constant vigilance and adaptation in global health strategies. Credit: SciTechDaily.com
The JN.1 COVID-19 variant, which emerges in late 2023, marks a significant change in the virusThe evolution of the disease emphasizes the need for sustained efforts in global health.
Since it was detected in August 2023the JN.1 variant of COVID has spread widely. It has become dominant in Australia and worldwidedriving the biggest wave of COVID 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 in January strongly stated COVID was an ongoing threat to global health, causing “too many” preventable diseases with worrying potential for long-term health consequences.
“#COVID-19 It remains a threat to global health and is causing too much burden when we can prevent it.
Five, ten years from now, what will we see in terms of cardiac deterioration, lung deterioration or neurological deterioration? We do not know”.
– @mvankerkhove of @WHO pic.twitter.com/yB73YXekhb— United Nations Geneva (@UNGeneva) January 12, 2024
JN.1 is significant. First as a pathogen: it is a surprisingly new version of SARS-CoV-2 (the virus that causes COVID) and is rapidly displacing other circulating strains (omicron XBB).
It is also important for what it says about the evolution of COVID. Typically, SARS-CoV-2 variants look quite similar to what came before, accumulating only a few mutations while giving the virus a significant advantage over its parent.
However, occasionally, as was the case when omicron (B.1.1.529) emerged two years ago, variants emerge seemingly out of nowhere that have markedly different characteristics than what came before. This has important implications for disease and transmission.
Until now, it was unclear that this “breakthrough” evolution would occur again, especially given the continued success of the ever-evolving omicron variants.
JN.1 is so different and is causing such a wave of new infections that many are wondering if the WHO will recognize JN.1 as the next variant of concern with its own Greek letter. In any case, with JN.1 we enter a new phase of the pandemic.
Where did JN.1 come from?
The history of JN.1 (or BA.2.86.1.1) begins with the emergence of its parental lineage BA.2.86 around mid-2023, which originated from a much earlier (2022) omicron BA.2 subvariant.
Chronic infections Issues that may remain unresolved for months (if not years, in some people) likely play a role in the emergence of these variants of radical change.
In people with chronic infection, the virus silently tests and eventually retains many mutations that help it avoid immunity and survive in that person. For BA.2.86, this resulted in more than 30 mutations of the spike protein (a protein on the surface of SARS-CoV-2 that allows it to bind to our cells).
The large volume of infections occurring globally sets the stage for major viral evolution. SARS-CoV-2 continues to have a very high mutation rate. Consequently, JN.1 itself is already mutating and evolving quickly.
How is JN.1 different from other variants?
BA.2.86 and now JN.1 behave in a way that appears unique in laboratory studies in two ways.
The first concerns how the virus evades immunity. JN.1 has inherited more than 30 mutations in your spike protein. He also acquired a new mutation, L455Swhich further decreases the ability of antibodies (a part of the immune system’s protective response) to bind to the virus and prevent infection.
The second involves changes to the JN.1 form enters and replicates in our cells. Without delving into the molecular details, recent high-profile laboratory research from the USA and Europe observed that BA.2.86 enters lung cells similarly to preomicron variants such as delta. However, by contrast, preliminary work by Australia’s Kirby Institute using different techniques finds replication features that are better aligned with omicron lineages.
More research is important to resolve these different findings in cell entry because they have implications for where the virus may prefer to replicate in the body, which could affect the severity and transmission of the disease.
Whatever the case, these findings show that JN.1 (and SARS-CoV-2 in general) can not only navigate our immune system, but are finding new ways to infect cells and transmit them effectively. We need to further study how this manifests in people and how it affects clinical outcomes.
JN.1 has some features that distinguish it from other variants.
Is JN.1 more serious?
The radical evolution of BA.2.86, combined with the immune evasion characteristics in JN.1, has given the virus a global growth advantage far beyond the XBB.1-based lineages we face in 2023.
Despite these characteristics, evidence suggests that our adaptive immune system could still recognize and respond to BA.286 and JN.1 effectively. Updated vaccines, tests and monovalent treatments remain effective against JN.1.
There are two elements to “severity”: first, if it is more “intrinsically” serious (worse disease with infection in the absence of immunity) and second, if the virus has greater transmission, causing greater illness and death, simply because it infects. more people. The latter is certainly the case for JN.1.
Whats Next?
We simply don’t know whether this virus is on the evolutionary path to becoming the “next common cold” or not, nor do we have any idea what that time frame might be. While examining the trajectories of four historic coronaviruses could give us an idea of where we are headed, this should be considered only as one possible path. The emergence of JN.1 underlines that we are experiencing an ongoing COVID epidemic and that this appears to be the way forward for the foreseeable future.
We are now in a new pandemic phase: post-emergency. However, COVID remains the main infectious disease causing damage worldwide, both from acute infections and from long COVID. At a societal and individual level, we must rethink the risks of accepting wave after wave of infection.
Taken together, this underscores the importance of Comprehensive strategies to reduce transmission and impacts of COVIDwith the least taxation (such as clean indoor air interventions).
People are advised continue to take active steps to protect themselves and those around them.
For better pandemic preparedness for emerging threats and a better response to the current one, it is essential that continue global surveillance. The underrepresentation of low- and middle-income countries is a worrying blind spot. It is also crucial to intensify research.
Written by:
- Suman Majumdar – Associate Professor and Director of Health – COVID and Health Emergencies, Burnet Institute
- Brendan Crabb – Director and CEO, Burnet Institute
- Emma Pakula – Senior Research and Policy Officer, Burnet Institute
- Stuart Turville – Associate Professor, Immunovirology and Pathogenesis Programme, Kirby Institute, UNSW Sydney
Adapted from an article originally published in The conversation.