A COVID-19 variant that emerged in the middle part of last year now accounts for about 90 percent of all cases in the United States, according to the U.S. Centers for Disease Control and Prevention (CDC).
As of Jan. 20, the JN.1 variant specifically makes up about 85 percent of cases, the CDC said in an update. However, there are no signs that the variant causes more severe disease or hospitalizations than prior variants, officials and researchers have signaled.
In October 2023, when JN.1 was first reported via the CDC’s tracker, it made up about 1 percent of all U.S. cases. Since then, the variant has quickly spread, prompting an alert from the World Health Organization, which listed it as a “variant of interest.” It became the dominant COVID-19 strain in the United States in late December, officials said at the time.
The CDC notes that the vast majority of the U.S. population has either already had COVID-19 or received a vaccine since the start of the pandemic in early 2020.
Meanwhile, the CDC’s tracking data show that COVID-19 hospitalizations, case numbers, and emergency room visits are currently declining for the most recent reporting week ending Jan. 13. Emergency room visits fell by 19 percent, hospitalizations are down by 9.6 percent, and case numbers dipped by 1 percent, according to the agency.
While the numbers have risen in recent months, it’s still much lower than previous increases in the virus across the United States throughout the pandemic, the CDC’s historical data show.
The CDC has indicated that there is no evidence the variant causes different symptoms than prior versions, while an agency spokesperson in December responded to reports that claimed otherwise.
A spokesperson for the CDC said at the time that “there is no data that would indicate JN.1 infection produces different symptoms from other variants,” adding, “In general, symptoms of COVID-19 tend to be wide-ranging with all variants.”
“The types of symptoms and how severe they are usually depend more on a person’s immunity and overall health rather than which variant causes the infection,” the spokesperson said.
“There have been reports that COVID-19 may be associated with insomnia and anxiety in some patients, and therefore, that can be a general symptom of infection and not related to the variant.”
The agency “is constantly researching the effects of COVID variants and will update the public as we learn more,” the spokesperson added.
The CDC currently lists the symptoms of COVID-19 as fever, chills, sore throat, cough, runny nose or congestion, difficulty breathing, fatigue, loss of smell or taste, muscle aches, headaches, brain fog, and stomach issues including vomiting or diarrhea.
California Changes Rules
California recently adjusted its guidelines on how a person should isolate after testing positive for COVID-19, distancing itself from the CDC.
State guidelines released this month recommend that people who test positive and have mild symptoms can end their isolation if their symptoms improve, and if they’ve been without a fever—without taking medication—for 24 hours or more, according to a statement from the state’s health agency.
“We are now at a different point in time with reduced impacts from COVID-19 compared to prior years due to broad immunity from vaccination and/or natural infection, and readily available treatments available for infected people,” the California Health Department said in the statement.
“[The state’s new] policies and priorities for intervention are now focused on protecting those most at risk for serious illness, while reducing social disruption that is disproportionate to recommendations for prevention of other endemic respiratory viral infections,” it reads.
Since mid-2022, CDC guidelines stipulate that individuals with COVID-19 stay home for at least five days, regardless of whether they’re symptom-free or if they have them. After five days elapse and if the symptoms haven’t improved, individuals should isolate until they feel better and until they have been without a fever for at least a day.
California, along with other Democrat-dominated states, implemented more strict COVID-19 rules, including mandates for social distancing, lockdowns, vaccines, schools, and masks.

