Since it was detected in August 2023, the JN.1 variant of COVID has spread widely. It has become dominant in Australia and around the world, driving the biggest COVID wave 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 a continuing global health threat causing “far too much”
JN.1 is significant. First as a pathogen – it’s a surprisingly new-look version of SARS-CoV-2 (the virus that causes COVID) and is rapidly displacing other circulating strains (omicron XBB).
It’s also significant because of what it says about COVID’s evolution. Normally, SARS-CoV-2 variants look quite similar to what was there before, accumulating just a few mutations at a time that give the virus a meaningful advantage over its parent.
However, occasionally, as was the case when omicron (B.1.1.529) arose two years ago, variants emerge seemingly out of the blue that have markedly different characteristics to what was there before. This has significant implications for disease and transmission.
Until now, it wasn’t clear this “step-change” evolution would happen again, especially given the ongoing success of the steadily evolving omicron variants.
JN.1 is so distinct and causing such a wave of new infections that many are wondering whether the WHO will recognize JN.1 as the next variant of concern with its own Greek letter. In any case, with JN.1 we’ve entered a new phase of the pandemic.
Where did JN.1 come from?
The JN.1 (or BA.2.86.1.1) story begins with the emergence of its parent lineage BA.2.86 around mid-2023, which originated from a much earlier (2022) omicron sub-variant BA.2.
Chronic infections that may linger unresolved for months (if not years, in some people) likely play a role in the emergence of these step-change variants.
In chronically infected people, 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 attach to our cells).
The sheer volume of infections occurring globally sets the scene for major viral evolution. SARS-CoV-2 continues to have a very high rate of mutation. Accordingly, JN.1 itself is already mutating and evolving quickly.
How is JN.1 different to other variants?
BA.2.86 and now JN.1 are behaving in a manner that looks unique in laboratory studies in two ways.
The first relates to how the virus evades immunity. JN.1 has inherited more than 30 mutations in its spike protein. It also acquired a new mutation, L455S, which further decreases the ability of antibodies (one part of the immune system’s protective response) to bind to the virus and prevent infection.
The second involves changes to the way JN.1 enters and replicates in our cells. Without delving into the molecular details, recent high-profile lab-based research from the United States and Europe observed BA.2.86 to enter cells from the lung in a similar way to pre-omicron variants like delta. However, in contrast, preliminary work by Australia’s Kirby Institute using different techniques finds replication characteristics that are aligned better with omicron lineages.
Further research to resolve these different cell entry findings is important because it has implications for where the virus may prefer to replicate in the body, which could affect disease severity and transmission.
Whatever the case, these findings show JN.1 (and SARS-CoV-2 in general) can not only navigate its way around our immune system, but is finding new ways to infect cells and transmit effectively. We need to further study how this plays out in people and how it affects clinical outcomes.
Is JN.1 more severe?
The step-change evolution of BA.2.86, combined with the immune-evading features in JN.1, has given the virus a global growth advantage well beyond the XBB.1-based lineages we faced in 2023.
Despite these features, evidence suggests our adaptive immune system could still recognize and respond to BA.286 and JN.1 effectively. Updated monovalent vaccines, tests, and treatments remain effective against JN.1.
There are two elements to “severity”: first if it is more “intrinsically” severe (worse illness with an infection in the absence of any immunity) and second if the virus has greater transmission, causing greater illness and deaths, simply because it infects more people. The latter is certainly the case with JN.1.
What next?
We simply don’t know if this virus is on an evolutionary track to becoming the “next common cold” or not, nor have any idea of what that timeframe might be. While examining the trajectories of four historic coronaviruses could give us a glimpse of where we may be heading, this should be considered as just one possible path. The emergence of JN.1 underlines that we are experiencing a continuing epidemic with COVID and that looks like the way forward for the foreseeable future.
We are now in a new pandemic phase: post-emergency. Yet COVID remains the major infectious disease causing harm globally, from both acute infections and long COVID. At a societal and an individual level we need to re-think the risks of accepting wave after wave of infection.
Altogether, this underscores the importance of comprehensive strategies to reduce COVID transmission and impacts, with the least imposition (such as clean indoor air interventions).
People are advised to continue to take active steps to protect themselves and those around them.
For better pandemic preparedness for emerging threats and an improved response to the current one it is crucial we continue global surveillance. The low representation of low- and middle-income countries is a concerning blind spot. Intensified research is also crucial.
Written by:
- Suman Majumdar – Associate Professor and Chief Health Officer – 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 Program, Kirby Institute, UNSW Sydney
Adapted from an article originally published in The Conversation.
News
Studies detail high rates of long COVID among healthcare, dental workers
Researchers have estimated approximately 8% of Americas have ever experienced long COVID, or lasting symptoms, following an acute COVID-19 infection. Now two recent international studies suggest that the percentage is much higher among healthcare workers [...]
Melting Arctic Ice May Unleash Ancient Deadly Diseases, Scientists Warn
Melting Arctic ice increases human and animal interactions, raising the risk of infectious disease spread. Researchers urge early intervention and surveillance. Climate change is opening new pathways for the spread of infectious diseases such [...]
Scientists May Have Found a Secret Weapon To Stop Pancreatic Cancer Before It Starts
Researchers at Cold Spring Harbor Laboratory have found that blocking the FGFR2 and EGFR genes can stop early-stage pancreatic cancer from progressing, offering a promising path toward prevention. Pancreatic cancer is expected to become [...]
Breakthrough Drug Restores Vision: Researchers Successfully Reverse Retinal Damage
Blocking the PROX1 protein allowed KAIST researchers to regenerate damaged retinas and restore vision in mice. Vision is one of the most important human senses, yet more than 300 million people around the world are at [...]
Differentiating cancerous and healthy cells through motion analysis
Researchers from Tokyo Metropolitan University have found that the motion of unlabeled cells can be used to tell whether they are cancerous or healthy. They observed malignant fibrosarcoma cells and [...]
This Tiny Cellular Gate Could Be the Key to Curing Cancer – And Regrowing Hair
After more than five decades of mystery, scientists have finally unveiled the detailed structure and function of a long-theorized molecular machine in our mitochondria — the mitochondrial pyruvate carrier. This microscopic gatekeeper controls how [...]
Unlocking Vision’s Secrets: Researchers Reveal 3D Structure of Key Eye Protein
Researchers have uncovered the 3D structure of RBP3, a key protein in vision, revealing how it transports retinoids and fatty acids and how its dysfunction may lead to retinal diseases. Proteins play a critical [...]
5 Key Facts About Nanoplastics and How They Affect the Human Body
Nanoplastics are typically defined as plastic particles smaller than 1000 nanometers. These particles are increasingly being detected in human tissues: they can bypass biological barriers, accumulate in organs, and may influence health in ways [...]
Measles Is Back: Doctors Warn of Dangerous Surge Across the U.S.
Parents are encouraged to contact their pediatrician if their child has been exposed to measles or is showing symptoms. Pediatric infectious disease experts are emphasizing the critical importance of measles vaccination, as the highly [...]
AI at the Speed of Light: How Silicon Photonics Are Reinventing Hardware
A cutting-edge AI acceleration platform powered by light rather than electricity could revolutionize how AI is trained and deployed. Using photonic integrated circuits made from advanced III-V semiconductors, researchers have developed a system that vastly [...]
A Grain of Brain, 523 Million Synapses, Most Complicated Neuroscience Experiment Ever Attempted
A team of over 150 scientists has achieved what once seemed impossible: a complete wiring and activity map of a tiny section of a mammalian brain. This feat, part of the MICrONS Project, rivals [...]
The Secret “Radar” Bacteria Use To Outsmart Their Enemies
A chemical radar allows bacteria to sense and eliminate predators. Investigating how microorganisms communicate deepens our understanding of the complex ecological interactions that shape our environment is an area of key focus for the [...]
Psychologists explore ethical issues associated with human-AI relationships
It's becoming increasingly commonplace for people to develop intimate, long-term relationships with artificial intelligence (AI) technologies. At their extreme, people have "married" their AI companions in non-legally binding ceremonies, and at least two people [...]
When You Lose Weight, Where Does It Actually Go?
Most health professionals lack a clear understanding of how body fat is lost, often subscribing to misconceptions like fat converting to energy or muscle. The truth is, fat is actually broken down into carbon [...]
How Everyday Plastics Quietly Turn Into DNA-Damaging Nanoparticles
The same unique structure that makes plastic so versatile also makes it susceptible to breaking down into harmful micro- and nanoscale particles. The world is saturated with trillions of microscopic and nanoscopic plastic particles, some smaller [...]
AI Outperforms Physicians in Real-World Urgent Care Decisions, Study Finds
The study, conducted at the virtual urgent care clinic Cedars-Sinai Connect in LA, compared recommendations given in about 500 visits of adult patients with relatively common symptoms – respiratory, urinary, eye, vaginal and dental. [...]
