• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
HealthCoronavirus

COVID-19 variant JN.1 symptoms: Is ‘Pirola’ different from other Omicron spawn?

By
Erin Prater
Erin Prater
Down Arrow Button Icon
By
Erin Prater
Erin Prater
Down Arrow Button Icon
December 28, 2023, 2:05 PM ET
Updated January 22, 2024, 10:51 AM ET
Artistic rendering of a COVID-19 pathogen
Cases of diarrhea, which may or may not be related to new COVID variant JN.1, are reportedly on the rise. Illustration by Getty Images

COVID wastewater levels are trending steeply upward in the U.S. It may leave you wondering if your winter illness is because of humanity’s newest scourge or something different entirely.

As always, it’s impossible to distinguish COVID from the flu, RSV, and other common winter illnesses like rhinoviruses, enteroviruses, and parainfluenza viruses by symptoms alone. Even with the new, highly mutated COVID variant “Pirola” JN.1, now globally dominant, this remains true. What’s more, it’s possible to have two or more infections at the same time.

As always, testing—at a health care facility or at home, in the case of COVID—is the only true way to determine the source of your illness. And while you should consult your health care provider, if your symptoms are mild and you don’t have other health conditions, the cause may not matter.

Still, with a new COVID variant making a splash, it’s fair to wonder if coronavirus symptoms have changed or if precautions like masking are again warranted. Here’s what you need to know to manage the winter illnesses that are likely headed your way.

Are JN.1 symptoms different from normal COVID symptoms?

The jury is still out. Cases of diarrhea, which may or may not be related, are reportedly on the rise. This comes as speculation swirls that the virus might be taking up residence in the gut—versus like the upper respiratory tract, where Omicron tends to hang out, or the lower respiratory tract, where initial strains of COVID wreaked havoc.

Keep an eye out for GI symptoms and realize they could be signs of COVID, not just the stomach flu, experts advise. But as Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, points out, COVID has always caused GI symptoms in some, including nausea, vomiting, and diarrhea.

Otherwise, keep an eye out for the usual COVID symptoms, which may include:

  • Fever
  • Chills
  • Cough
  • Shortness of breath/difficulty breathing
  • Fatigue
  • Muscle/body aches
  • Headache
  • Sore throat
  • Congestion/runny nose

Is JN.1 causing more severe cases of COVID?

Once again, the jury is still out. What we do know, however, is that COVID hospitalizations are trending upward in the U.S. and elsewhere, as are cases of JN.1.

In the U.S., COVID hospital admissions had risen 10% week-over-week as of Dec. 16, according to the latest federal health data. And JN.1 was projected to lead U.S. COVID cases, estimated to be behind 44% of them as of Dec. 22.

Globally, reported sequences of JN.1 increased eightfold in a three-week period during late November into early December, according to the World Health Organization’s Dec. 22 COVID update. Reported hospitalizations rose 23% globally during that period.

But correlation does not equal causation. It’s important to note that sequencing of COVID samples and reporting of various metrics like hospitalizations and deaths have declined greatly since the height of the pandemic, meaning statistics could appear misleading. For example: Hospitalizations may be rising quicker than we realize. Or perhaps JN.1 is responsible for a smaller share of sequences than we know.

It’s also important to note that while COVID hospitalizations are on the rise globally, JN.1 may not be to blame—not entirely, at least. Population immunity—or the collective resistance to a virus in a group of people due to vaccination and/or prior infection—wanes after three to six months, on average. With COVID vaccine and booster uptake at low levels—only 18% of U.S. adults have received the latest booster, released in September—the disease will spread more widely, and severe outcomes like hospitalizations and deaths could become more common, regardless of variant.

Do COVID tests still work against JN.1?

At-home COVID tests remain as accurate as they’ve ever been, experts say. But they caution that many infected people test too early or too late, when viral loads are low and unlikely to turn a test positive. If you have symptoms but test negative, wait another couple of days and test again, experts recommend.

What viruses are circulating in the U.S. this winter?

In short: the usual suspects. Around 12% of all tests for COVID, flu, and RSV performed in the U.S. were returning positive mid-December, according to the latest available data from the U.S. Centers for Disease Control and Prevention. For some perspective, a long-ago abandoned goal from the World Health Organization and other public health agencies was a test-positivity rate of below 5%, for communities that wanted to cast aside pandemic precautions.

Should I be masking this winter?

Experts are increasingly recommending it, and not just because of COVID. Some hospitals, like those in New York and Illinois, are again requiring masks because of high levels of respiratory pathogen circulation in their area. And Yolo County in Northern California is recommending masking in public spaces due to surging levels of COVID and RSV.

Dr. Stuart Ray, vice chair of medicine for data integrity and analytics at Johns Hopkins’ Department of Medicine, recommends “wearing an effective respirator in public spaces, especially indoors, when it doesn’t interfere with essential tasks.”

“Not a bad way to keep your face warm, too,” he adds.

The Fortune 500 Innovation Forum will convene Fortune 500 executives, U.S. policy officials, top founders, and thought leaders to help define what’s next for the American economy, Nov. 16-17 in Detroit. Apply here.
About the Author
By Erin Prater
See full bioRight Arrow Button Icon

Latest in Health

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • World's Most Admired Companies
  • See All Rankings
  • Lists Calendar
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Health

hoskins
Commentaryoffices
Gensler Co-Chair: Hot-desking was supposed to save money. It may be costing you your culture
By Diane HoskinsApril 30, 2026
20 minutes ago
raw milk
Politicsmilk
Risk of paralysis, bacteria, even death is no match for Americans’ thirst for raw milk
By Laura Ungar, Jonel Aleccia and The Associated PressApril 29, 2026
15 hours ago
The Best Protein Shakes of 2026: Tasted and Approved by Nutrition Experts
HealthDietary Supplements
The Best Protein Shakes of 2026: Tasted and Approved by Nutrition Experts
By Christina SnyderApril 29, 2026
21 hours ago
aging
HealthLongevity
We’re the CEOs of Peloton and the Hospital for Special Surgery. Living longer isn’t enough, we need to live better, too
By Bryan T. Kelly and Peter SternApril 29, 2026
22 hours ago
AI is changing who gets to be an expert. Are your colleagues ready to become ‘directors of intelligence’?
AIProductivity
AI is changing who gets to be an expert. Are your colleagues ready to become ‘directors of intelligence’?
By Bruce BroussardApril 29, 2026
1 day ago
Robert F. Kennedy Jr. sits at a cafeteria table with schoolchildren.
EconomyEducation
More than two-thirds of U.S. schools say they’re unable to afford the cost of student free lunch—and MAHA’s dietary guidelines may make it worse
By Sasha RogelbergApril 29, 2026
1 day ago

Most Popular

Apple cofounder Ronald Wayne—whose stake would be worth up to $400 billion had he not sold it in 1976—says that at 91, he has no regrets
Success
Apple cofounder Ronald Wayne—whose stake would be worth up to $400 billion had he not sold it in 1976—says that at 91, he has no regrets
By Preston ForeApril 27, 2026
3 days ago
‘Take the money and run’: Johns Hopkins economist Steve Hanke on why the UAE quit OPEC
Energy
‘Take the money and run’: Johns Hopkins economist Steve Hanke on why the UAE quit OPEC
By Shawn TullyApril 29, 2026
1 day ago
‘The cost of compute is far beyond the costs of the employees’: Nvidia executive says right now AI is more expensive than paying human workers
AI
‘The cost of compute is far beyond the costs of the employees’: Nvidia executive says right now AI is more expensive than paying human workers
By Sasha RogelbergApril 28, 2026
2 days ago
Jamie Dimon gets candid about national debt: ‘There will be a bond crisis, and then we’ll have to deal with it’
Economy
Jamie Dimon gets candid about national debt: ‘There will be a bond crisis, and then we’ll have to deal with it’
By Eleanor PringleApril 29, 2026
24 hours ago
‘They left me no choice’: Powell isn’t going anywhere—blocking Trump from another Fed appointee
Banking
‘They left me no choice’: Powell isn’t going anywhere—blocking Trump from another Fed appointee
By Eva RoytburgApril 29, 2026
16 hours ago
More than two-thirds of U.S. schools say they’re unable to afford the cost of student free lunch—and MAHA’s dietary guidelines may make it worse
Economy
More than two-thirds of U.S. schools say they’re unable to afford the cost of student free lunch—and MAHA’s dietary guidelines may make it worse
By Sasha RogelbergApril 29, 2026
1 day ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.