On December 7, 2023, no one wants to hear about holiday gatherings or travel plans being threatened, but the rise of a new COVID-19 variant, JN.1, is causing concern among experts who say it could jeopardize these good times.
The good news is that current research suggests that the 2023–2024 COVID-19 vaccine apparently works against this latest variant. However, so few people have received the latest vaccine – less than 16% of adults in the US – that some experts believe it’s time for the CDC to urge the unvaccinated public to do so now so that antibodies can take effect before the holiday celebrations.
“A significant wave [of JN.1] has begun here and could be mitigated through high booster uptake and containment measures,” said Eric Topol, MD, Professor and Executive Vice President of Scripps Research in La Jolla, California, and Editor-in-Chief of Medscape, sister site of WebMD.
Meanwhile, COVID metrics are beginning to rise again. In the week ending November 25, nearly 10,000 people were hospitalized in the US due to COVID, a 10% increase from the previous week, according to the CDC.
Who’s who in the lineage?
JN.1, a subvariant of Omicron, was first detected in the US in September and is described by the World Health Organization as a „notable lineage“ of the Omicron subvariant BA.2.86. When BA.2.86, also known as Pirola, was first identified in August, it appeared to be significantly different from other variants, sparking concerns that it could be more contagious than previous ones, even for people with immunity from vaccinations and previous infections, said the CDC.
“JN.1 is Pirola’s offspring,” said Rajendram Rajnarayanan, PhD, Deputy Dean of Research and Associate Professor at the New York Institute of Technology of Arkansas State University, who maintains a database of COVID-19 variants. He said that the BA.2.86 variant and its offspring are concerning due to the mutations.
How widespread is JN.1?
According to the CDC, BA.2.86 is expected to account for 5%-15% of the circulating variants in the US as of November 27th. The agency stated, „The expected public health risk posed by this variant, including its descendant JN.1, is low.“
Currently, JN.1 is being reported more frequently in Europe, according to Rajnarayanan, but some countries have better reporting data than others. “It has probably spread to every country tracking COVID,” he said, due to mutations in the spike protein that make it easier to bind and infect.
Vaccine efficacy against JN.1 and other new variants
The new monovalent vaccine XBB.1.5 provides protection against XBB.1.5, another Omicron subvariant, as well as JN.1 and other „emerging“ viruses, reported a team of researchers on November 26th in a study on bioRxiv, which has not yet been peer-reviewed.
The researchers reported that the updated vaccine, when administered to uninfected individuals, increased antibodies against XBB.1.5 by about 27 times and against JN.1 and other emerging viruses by 13 to 27 times.
Vaccine uptake in 2023–2024 low
In November, the CDC released the first detailed estimates of who had been vaccinated. As of November 18, less than 16% of US adults had been vaccinated, with nearly 15% indicating they plan to get vaccinated. The vaccination rate among children is even lower, with only 6.3% of children informed about the latest vaccine and 19% of parents indicating they plan to vaccinate their children in 2023–2024.
While some experts predict a peak in the coming weeks due to JN.1, Topol said that it’s impossible to predict exactly how JN.1 will develop. “There won’t be a repeat of November 2021,“ Rajnarayanan predicted when Omicron emerged. Within four weeks of the World Health Organization classifying Omicron as a variant of concern, it had spread worldwide.
Mitigation measures can help, said Rajnarayanan. He suggested:
- Get the new vaccine and encourage particularly vulnerable family members and friends to do so.
- If gathering indoors for the holidays, improve ventilation in the house where possible.
- Wear masks at airports and on planes and other public transportation.