The JN.1 variant seems more transmissible than other strains, but it isn’t likely to cause more severe Covid.
Covid cases appear to be climbing, according to Dr. Mandy Cohen, the director of the Centers for Disease Control and Prevention — and one particular variant seems to be fueling the virus’ spread.
JN.1, as the variant is known, now accounts for around 44% of Covid cases in the U.S., up from 8% just four weeks ago, according to the CDC.
“We are seeing JN.1 quickly become the dominant version of the Covid virus, which tells us it is more transmissible,” Cohen said in a phone interview. “The good news is we don’t see an increase in severity.”
The variant is also picking up steam globally. It accounted for 27% of genetic sequences submitted to a global virus database called GISAID in the week that ended Dec. 3, up from 10% in the week that ended Nov. 19.
The World Health Organization declared JN.1 a “variant of interest” Tuesday — a designation that applies to variants that are driving new cases and have genetic changes that could help them spread or evade immunity.
But so far, the illness caused by JN.1 — which, like all other variants that have gained dominance since early 2022, is a descendant of omicron — doesn’t seem any more severe than earlier Covid cases.
Neither the WHO nor the CDC collects regular data on how Covid symptoms are evolving over time, so it’s hard to assess whether infections are presenting differently. However, doctors say they haven’t noticed a new trend.
“The symptoms of JN.1 seem to be very similar, if not the same, as others,” said Dr. Molly Fleece, a hospital epidemiologist at University of Alabama at Birmingham Medicine.
Many recent Covid patients have reported sore throats as their first symptoms, often followed by congestion. The illness’ past hallmarks, such as a dry cough or the loss of taste or smell, have become less common, according to doctors.
Severe cases, meanwhile, are still characterized by shortness of breath, chest pain or pale, gray or blue skin, lips or nail beds — an indicator of a lack of oxygen.
But on the whole, Covid symptoms are milder than they were early in the pandemic.
Fleece said JN.1 is spreading at an unfortunate time as people travel and gather indoors.
“If we have a variant that is extremely easy to spread among people, that’s extremely important to think about going into the holidays,” she said. “Just the ease of transmissibility, especially being an omicron descendant — we saw how easily omicron spread throughout communities — should make everyone concerned.”