As the holiday season comes to an end and Covid-19 cases begin to rise, a variant called JN.1 has now become the most common strain of the virus spreading in the United States.
JN.1, from the BA.2.86 variant and first detected in the United States in September, accounted for 44% of Covid cases nationwide as of mid-December, up from around 7 percent in late November, according to data from the Centers for Disease Control and Prevention.
To some extent, this jump was predictable. “Variants take a while to show up,” said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center. “Then they accelerate, they spread widely, and just when they do, after several months, a new variant appears.”
JN.1’s momentum this month suggests it may be more transmissible or more effective at evading our immune systems than other variants currently circulating, according to a report. CDC report published on December 22. The agency said Covid remains “a serious threat to public health”, particularly for those who have historically been at high risk of severe illness, such as the elderly, infants, people with compromised immune systems. weakened or chronic health problems and those who are pregnant.
JN.1 doesn’t seem to cause serious illness in most other people, experts say, although even a mild case can still make you feel “pretty unhappy for three or four days,” Dr. Schaffner said. . Symptoms of a JN.1 infection are similar to those caused by previous Covid variants, including a cough, fever, body aches and fatigue.
To protect yourself from serious infections and illnesses, experts continue to recommend wearing masks, improving indoor ventilation when possible, staying home when sick, and getting vaccinated against Covid.
Preliminary research shows that the updated Covid vaccines released in September produce effective antibodies against JN.1, which is distantly related to the XBB.1.5 variant that the vaccines were designed to target. People may not develop as many antibodies to JN.1 as they do to XBB.1.5, but the levels should still decrease the risk.
“For those who have been recently infected or boosted, cross-protection against JN.1 should be decent, based on our laboratory studies,” said Dr. David Ho, a virologist at Columbia University who led the research on the JN.1 and Covid vaccines, which was published as a pre-printed document in early December. Rapid tests also remain a valuable tool, and the CDC said tests already on the market work well to detect JN.1.
There are signs that Covid cases are increasing again. There were just under 26,000 hospitalizations due to Covid the week of December 10, an increase of 10% from the 23,000 hospitalizations the week before. But Covid hospitalizations are still much lower than they were during the peak of the first Omicron wave in January 2022, and so far only about half of what they were during the peak of the tripledemic l This past winter, when Covid-19, flu and RSV cases all spiked at the same time.
It’s too early to know whether JN.1 is responsible for the increase in hospitalizations or whether cases are rising in part because of increased travel and large gatherings for Thanksgiving and winter holidays.
“When people are gathered near each other, having parties, traveling, etc., these are the kinds of circumstances in which all respiratory viruses, including JN.1, have opportunities to spread,” Dr. Schaffner said. Covid also generally has some seasonality, he added; Countries in the Northern Hemisphere tend to see a lull in cases in the fall before infections and hospitalizations increase again in winter.
JN.1 will most likely remain the dominant version of the coronavirus until the spring, Dr. Schaffner said. He and other experts noted that while vaccines offer protection against this virus and other variants, uptake remains low, with only 18 percent of adults who received the last injections. Experts said everyone should consider getting vaccinated, especially those who are over 65, immunocompromised, have health conditions that put them at higher risk of serious illness or are traveling to visit loved ones. loved ones who may be vulnerable.
“Give yourself a New Year’s gift by getting vaccinated if you haven’t yet,” Dr. Schaffner said.
