There’s yet another colorful addition to the pandemic lexicon—“flurona”—but it doesn’t refer to a new variant or even a new condition. The made-up term describes simultaneous infection with both influenza and SARS-CoV-2, the virus that causes COVID-19.
The two diseases do not combine to make some hybrid form of either virus, which makes “flurona” a bit of a fearmongering misnomer. But co-infection is becoming more common. Having COVID-19 and the flu at the same time has been a possibility since the beginning of the pandemic, but until now, rigorous safety precautions largely prevented such concerns from coming to fruition. “Everybody was basically hunkered down—we shuttered our windows and closed our doors. We masked up. Schools were out and daycares went down,” says Dr. Frank Esper, a physician at the Cleveland Clinic Children’s Center for Pediatric Infectious Diseases. “So all the viruses took a nosedive.” That’s no longer the case. “We’re seeing many, many people who have the coronavirus as well as a second or even third germ at the same time,” Esper says, and that could translate to an increasing number of so-called flurona cases.
Earlier this week, Texas Children’s Hospital said that a child who was infected with both influenza and COVID-19 was recovering at home. Los Angeles County reported its first case of flurona in a teenager who had just returned from a family trip to Mexico. He reportedly does not have serious symptoms and is recovering at home. Israel recently recorded its first case in an unvaccinated pregnant woman who experienced mild symptoms, and instances have been detected in Brazil and Hungary.
Here’s what to know about co-infection with the flu and COVID-19:
Is flurona new?
No. Having more than one virus at the same time is not a novel concept and has become more common over the last several decades, Esper says, so having the flu and coronavirus at the same time isn’t surprising. “It’s important for people to know that a lot of these co-infections, we’ve seen them for decades,” he says. “This is not a new phenomenon” and not cause for panic.
Coinfection was already happening in 2020, when research conducted at Tongji Hospital in Wuhan, China, found that nearly 12% of the 544 patients infected with COVID-19 also had influenza. Another 2020 study found that of nearly 2,000 patients hospitalized with the coronavirus in New York City, 42—2.1%—were co-infected with some other virus, and one was co-infected with the flu. The same year, researchers in Northern California found that about 21% of specimens positive for COVID-19 were also positive for another pathogen, most frequently rhinovirus.
Will flurona be more common this year?
Almost definitely. The highly contagious Omicron variant continues to whip around the globe, leading to record-high cases nearly every day. The flu, which is a respiratory infection, circulates during the fall and winter, usually peaking between December and February. While the U.S. Centers for Disease Control and Prevention (CDC) says flu activity is still low nationally, it’s steadily increasing.
Like SARS-CoV-2, the flu spreads through droplets in the air when people cough, sneeze or talk to each other. Less frequently, it spreads via contaminated surfaces. For example, if someone with the flu touched a grocery store shelf, and then you did—and proceeded to rub your eyes or put your hand in your mouth—you could become infected. The flu can spread from up to approximately 6 feet away.
“The discussion about COVID and influenza didn’t happen last year because there was no influenza really going around,” says Dr. Abinash Virk, an infectious disease specialist with the Mayo Clinic. Vaccines weren’t available yet, so mask mandates were in effect and people were social distancing and skipping social gatherings. “This year, influenza has already picked up,” Virk says. “So yes, we are worried that people will get both infections.”
Also concerning: Fewer people are getting the flu shot this year than in previous years, Virk says. As of the end of November, for example, 47.5% of pregnant people had gotten their shot, which is nearly 15 percentage points lower than the same time last year.
If I got the flu shot and am vaccinated against COVID-19, can I still get co-infection?
Yes. “It’s not like you get the vaccine and you’re bulletproof protected,” Virk says. However, the best way to prevent hospitalization and severe illness is to get vaccinated against both viruses. “You may still get a mild infection—but hopefully it’ll only be a mild infection.”
There’s some evidence that this year’s flu shot doesn’t match the circulating strain particularly well. Manufacturers produce shots designed to combat four strains that circulated during the previous season; that was difficult this year, since the pandemic essentially flattened the flu in 2020-2021. Still, it’s important to get the shot. “It doesn’t mean you’re not going to get protection,” Esper says. Almost everyone ages 6 months and over is eligible, and it’s especially encouraged for pregnant people, older adults, young kids and those with compromised immune systems.
What are the symptoms of flurona?
COVID-19 and influenza cause similar symptoms: fever, coughing, fatigue, sore throat, a runny nose and muscle aches. Esper anticipates that those with co-infection wouldn’t experience unique symptoms.
Patients hospitalized with a dual infection will be treated based on their risk of severe illness, Virk says. That might include Tamiflu, an antiviral that can lessen the amount of time one is sick with the flu and cut the risk of serious complications and death, and COVID-19-specific treatments such as oxygen, monoclonal antibodies and IL6 receptor blockers. The exact treatment program will depend on each patient’s circumstances and personal risk factors. For example, patients at “higher risk of having severe lung disease,” such as those with obesity, will receive more aggressive treatment, Virk says.
It’s possible that co-infection could lead to longer illness: In one of the early studies in Wuhan, COVID-19 patients who also had influenza shed SARS-CoV-2 for 17 days, as compared to an average of 12 days for those with only one infection.
Does having the flu at the same time increase the severity of COVID-19?
“The jury’s still out,” Esper says, “and that’s something we’re very interested in seeing.” But there’s reason for optimism: research has historically indicated that people with two or three viruses at the same time don’t experience more severe illness than if they just had one. “Everybody knows flu is bad; everybody knows coronavirus is bad,” he says. “You put the two together, you think you’re even worse. For the most part, virus-wise, we don’t see that.”
Still, Esper adds, every virus can manifest differently, and so can specific pairings. So if you have both virus A and virus B, you might experience more severe disease; mix up a virus C and virus D cocktail, and you wouldn’t see such an effect. That underscores the need for more data to draw a conclusion.
Are kids at greater risk?
In general, young children are six to eight times more likely to have multiple viruses at the same time compared to adults, Esper says—partly because they’re exposed to so many germs at places like daycare. Plus, he points out, flu shot rates among kids tend to be low. According to data from the CDC, 58.6% of children 6 months through 17 years got inoculated during the 2020-2021 flu season, a decrease of about 5 percentage points compared to 2019-2020. And kids under 5 still can’t get vaccinated against the coronavirus, leaving them particularly vulnerable to infection.
How can I protect against flurona?
The good news is that we already know how to stay healthy. “If there was one big takeaway over the last 12 months, it’s how little respiratory viruses we saw because everybody was masking up and washing their hands and distancing,” Esper says. “So if you’re like, ‘Do I really have to wear a mask?’ It’s not just protecting you against the coronavirus. It’s also protecting against the influenza virus, RSV [respiratory syncytial virus], the rhinovirus and all these other viruses out there.”
If you haven’t yet, get vaccinated against both COVID-19 (including a booster after five months) and the flu. Wear a mask in public, get tested frequently and be smart about gatherings. The word “flurona” might be new, but the guidance is not.