January 09, 2024<\/p>\n\n\n\n
In early November 2023, the JN.1 variant caused less than 5% of COVID-19 cases in the U.S. Now it is estimated to cause more than 60% of them<\/a>. Virologists including Andy Pekosz<\/a>, PhD, a professor in Molecular Microbiology and Immunology<\/a>, are paying attention. <\/p>\n\n\n\n Here, Pekosz explains what virologists are seeing, what this new variant means for case rates and treatments, and why it\u2019s so important for more people to get the updated COVID-19 vaccine<\/a> rolled out this fall.<\/p>\n\n\n\n A SARS-CoV-2 variant called BA.2.86 emerged a few months ago and caught virologists\u2019 attention because it contains many more mutations\u2014about 30 of them\u2014to evade immunity than any other variant circulating at that time. However, the BA.2.86 variant never came to dominate among the group of SARS-CoV-2 variants that were circulating in the late summer\/early fall of 2023. The JN.1 variant is a descendant of BA.2.86 that has acquired the ability to transmit efficiently through an additional one or two mutations. It has the immune evasion of its parent but has now mutated to transmit more efficiently. <\/p>\n\n\n\n The increase in the number of cases caused by JN.1 corresponds to an overall increase in COVID-19 cases. Symptoms of JN.1 infection are very similar to those of previous omicron variants, and it doesn\u2019t seem to cause more severe disease, either. <\/strong>There is some suggestion that JN.1 may be causing more diarrhea than previous variants, but we don\u2019t have any firm data supporting that yet. <\/p>\n\n\n\n This latest variant should be a reminder that we have tools to fight off COVID infection and minimize severe disease: Tests detect JN.1, the new vaccines<\/a>protect against severe disease, and antivirals are still capable of treating infection from JN.1. We just have to use these tools more effectively than we have over the last six months. <\/p>\n\n\n\n So far, only 8% of children and 19% of adults<\/a> have received the latest vaccine, so a lot of people are missing out on protection from this virus. <\/p>\n\n\n\n The period of infectiousness for JN.1 is very similar to that of the other omicron variants that have been circulating over the past year: You are contagious one to two days before your symptoms begin, and you are still contagious for at least two to three days after your symptoms begin\u2014though some people can continue to have the detectable live virus for up to a week after symptom onset. After exposure, it may take five days or more before you begin to develop symptoms. <\/p>\n\n\n\n The older vaccines were based on SARS-CoV-2 variants that are very different from variants circulating now. That, combined with the fact that your immunity from vaccination or infection tends to drop off over time, means that you won\u2019t get a lot of protection from COVID-19 if you are relying on the vaccines you received nearly a year ago. It’s very similar to why we have annual influenza vaccines: The virus is changing, so we have to change the vaccine to make sure it is a good match with the virus variants that are causing infection right now. <\/p>\n\n\n\n While the JN.1 variant does have a number of mutations that help it avoid immunity, laboratory studies suggest that the updated COVID-19 vaccine does increase the amount of antibodies that can recognize JN.1, and it is still effective in protecting against severe disease. You really need the newest COVID-19 vaccine formulation to be protected from severe illness from JN.1 and other recent variants.<\/p>\n\n\n\n No. Getting vaccinated now can provide protection during this surge. Don\u2019t wait. This is particularly important for those in high-risk groups, but it goes for all eligible individuals. <\/p>\n\n\n\n Paxlovid is still working very well, particularly in high-risk populations, but it\u2019s not being prescribed as frequently as it should be. It\u2019s important to remember that Paxlovid needs to be taken as soon as possible after symptoms begin, within five days of symptom onset is the guidance, but the earlier, the better. This means it is particularly important to test when you start feeling sick and then get a prescription if you test positive.<\/p>\n\n\n\n Case rates will likely go up. We\u2019re coming out of a period when we already expected transmission to go up, due to increased travel and holiday gatherings. For the rest of January and into February, we will continue to have a high amount of respiratory virus activity that includes COVID-19 cases. Now is the time to get vaccinated if you haven\u2019t already, get some COVID-19 tests available for free from the U.S. government<\/a>, and make sure your local pharmacy can fill a COVID-19 antiviral prescription if you do end up testing positive.<\/p>\n\n\n\n Aliza Rosen is a digital content strategist at the Johns Hopkins Bloomberg School of Public Health.<\/em><\/p>\n\n\n\n Melissa Hartman is the managing editor of <\/em>Hopkins Bloomberg Public Health <\/a>magazine and associate director of editorial at the Bloomberg School.<\/em><\/p>\n\n\n\n Preventing Another \u201cTripledemic\u201d with Vaccines for Flu, COVID, and RSV<\/a><\/p>\n\n\n\n How does COVID-19 variant JN1 compare to other variants?<\/p>\n\n\n\n What to Know About the Updated COVID-19 Vaccine for Fall\/Winter 2023<\/a><\/p>\n\n\n\n Two New RSV Products to Protect Infants<\/a><\/p>\n\n\n\n Blog Editor<\/a>15 January 2024<\/p>\n\n\n\n With the emergence at the end of last year of COVID-19 variant JN.1, there are questions about how it compares to the many other variants that have been identified.<\/p>\n\n\n\n JN.1 descends from variant BA.2.86 and has an additional mutation in the spike protein. It has recently become the most widely circulating variant in the US<\/a> as well as in France<\/a>. As of January 2024, approximately 60% of English cases are caused by JN.1.<\/p>\n\n\n\n UKHSA is continuing to monitor data relating to variants both in the UK and internationally, including close monitoring of the JN.1 variant, and assessment of severity and vaccine effectiveness. There is no change to the wider public health advice at this time.<\/p>\n\n\n\n There are no reports of people becoming more ill with this COVID-19 variant than with previous ones.<\/p>\n\n\n\n It is important to note that we will need more data to draw any conclusions about the effect of these mutations on transmissibility and severity of the variant. In this blog post we\u2019ll outline what we know so far and what action we are taking.<\/p>\n\n\n\n It\u2019s normal for viruses to mutate and change, and more widely we\u2019re still getting to grips with how the healthcare system responds to the ebb and flow of seasonal cases. As more data becomes available on this variant, we\u2019ll have a better understanding of how it interacts with our immune systems and how to optimise our protection and as well as actions we can take to keep the most vulnerable safe and live our lives as normally as possible.<\/p>\n\n\n\n If you have symptoms of a respiratory infection, such as COVID-19, and you have a high temperature or do not feel well enough to go to work or carry out normal activities, you should avoid contact with vulnerable people and stay at home if possible.<\/p>\n\n\n\n For those of us who absolutely can\u2019t stay at home, our Living with COVID guidance<\/a> is unchanged, and outlines how to prevent transmission to others.<\/p>\n\n\n\n Vaccines remain our best defence against severe disease and hospitalisation from flu and COVID-19. That\u2019s why we\u2019re asking over-65s, anyone in a clinical risk group, and anyone living in a household with someone who is in a clinical risk group, to come forward for their vaccination<\/a>. Their protection since their last vaccination will have waned and they remain at increased risk from a respiratory infection this winter. It\u2019s also important to note that COVID-19 isn\u2019t a special case; respiratory infections can be unpredictable, and we\u2019re asking similar groups to get vaccinated against flu.<\/p>\n\n\n\n The last date that the seasonal COVID-19 vaccination will be available is 31 January 2024.<\/p>\n\n\n\n We publish the latest surveillance data for COVID-19 and other respiratory illnesses weekly, to the UKHSA data dashboard<\/a>. We\u2019re also getting vital data from those who are admitted to hospital with symptoms, and we are utilising genome sequencing to understand which variants people are most vulnerable to.<\/p>\n\n\n\n There are also specific surveillance programmes in place, where small sample groups are tested regularly. These allow us to monitor trends in the wider community.<\/p>\n\n\n\n Hospital is where we will see the more severe cases, and we will be monitoring the numbers of people attending with COVID-19 symptoms very carefully. This will help us understand the growth rate and transmission potential of the new variant.<\/p>\n\n\n\n We continue to collaborate globally with health organisations in other countries, the World Health Organisation<\/a> and initiatives such as the Global Influenza Surveillance & Response System (GISAID)<\/a> to ensure that we have the most current data.<\/p>\n\n\n\n When a new variant appears on our radar, at the initial stages it is often quite difficult to know whether the mutations provide any advantages to the virus. Genetic mutations happen all the time, and in some cases have been known to make a virus less transmissible or cause a milder reaction in people.<\/p>\n\n\n\nWhat is JN.1?<\/strong><\/h4>\n\n\n\n
What\u2019s happening now with this variant?<\/strong><\/h4>\n\n\n\n
What\u2019s most important to understand about this variant?<\/strong><\/h4>\n\n\n\n
What does the transmission timeline look like for JN.1?<\/strong><\/h4>\n\n\n\n
Are people who had an older vaccine or who\u2019ve had COVID from another variant likely to be reinfected by JN.1?<\/strong><\/h4>\n\n\n\n
Do we know yet how well this fall\u2019s COVID-19 vaccines work against this variant?<\/strong><\/h4>\n\n\n\n
COVID numbers have been rising for a few weeks now. Is it too late to get the vaccine?<\/strong><\/h4>\n\n\n\n
Is Paxlovid effective against JN.1? <\/strong><\/h4>\n\n\n\n
What might we expect in terms of case rates over the next few weeks?<\/strong><\/h4>\n\n\n\n
RELATED:<\/strong> <\/h2>\n\n\n\n
If people become unwell, and are unsure if they have COVID-19, what should they do?<\/h2>\n\n\n\n
Why should people come forward for their vaccine?<\/h2>\n\n\n\n
What surveillance systems are in place?<\/h2>\n\n\n\n
What is the UKHSA doing to tackle the new variant?<\/h2>\n\n\n\n