Several viruses are circulating at elevated levels right now, though none of them are new. As of late February 2026, seasonal influenza is the dominant respiratory virus in the United States, followed by RSV and COVID-19. There isn’t a novel pathogen driving a new outbreak, but the overlap of these three viruses is making a lot of people sick at once.
What’s Circulating Right Now
CDC surveillance data for the week ending February 21, 2026, shows influenza leading with a 17.9% positivity rate among tests, RSV at 8.6%, and COVID-19 at 4.3%. Influenza A is declining nationally while influenza B is picking up in most parts of the country. RSV is elevated and still increasing in some regions. COVID-19 activity is decreasing overall but remains elevated in pockets.
If you’re feeling run down with a cough, fever, or body aches right now, flu is statistically the most likely culprit. But all three of these viruses produce similar symptoms, which makes it hard to tell them apart without a test.
How to Tell Flu, COVID, and RSV Apart
Honestly, you often can’t based on symptoms alone. All three cause fever, cough, fatigue, congestion, and body aches. A few patterns can offer clues, though. COVID-19 is more likely to cause a change in taste or smell. It also has a longer incubation period: symptoms typically show up two to five days after exposure (and sometimes up to 14 days), while flu symptoms appear within one to four days. RSV tends to hit hardest in very young children and older adults, often producing wheezing and difficulty breathing.
The most reliable way to know is a test. Many pharmacies carry combination tests that check for both flu and COVID at once. If you’re in a high-risk group or your symptoms are severe, knowing which virus you have matters because treatments differ.
Flu Treatment Works Best Within 48 Hours
Antiviral medications for the flu can shorten your illness by about a day and reduce the severity of symptoms, but the window is tight. They work best when started within one to two days of your first symptoms. The most common option is a pill or liquid taken twice daily for five days. There’s also a single-dose pill option for uncomplicated flu in people five and older. Your doctor can help determine which is appropriate based on your age and health status.
For COVID-19, antivirals are similarly most effective when taken early. If you test positive and are at higher risk for severe illness due to age, pregnancy, or underlying conditions, contact a healthcare provider promptly to discuss treatment options.
Bird Flu: Low Risk but Worth Watching
You may have seen headlines about H5N1 bird flu in humans. The CDC has confirmed 71 human cases in the United States since February 2024, spread across 13 states including California, Texas, Colorado, and several Midwestern states. The vast majority of these cases were detected through monitoring of people who had direct contact with infected poultry or dairy cattle, not through person-to-person spread.
The CDC currently rates the public health risk from H5N1 as low. This is not what’s making people sick in the general population. It remains primarily an occupational hazard for farmworkers, and there’s no evidence of sustained human-to-human transmission.
Mpox Clade 1b Is Spreading Slowly
A newer strain of mpox, called clade 1b, has been circulating internationally since it was first identified in the eastern Democratic Republic of the Congo. Beginning in fall 2025, several Western European countries reported cases among people with no travel history, which signals limited local spread. Over 150 clade 1b cases have been reported in high-income countries since January 2024, with no deaths.
Clade 1b spreads primarily through intimate or sexual contact, then within households. Its case fatality rate is less than 0.5%, significantly lower than the related clade 1a strain. Additional cases in Europe and the United States are expected, but this is not a respiratory virus and spreads very differently from flu or COVID.
Global Alerts: Dengue and Chikungunya
The CDC has active alerts for dengue at a global level and chikungunya outbreaks in Bolivia, Seychelles, and Suriname. Both are mosquito-borne viruses, so they’re relevant primarily for travelers heading to tropical regions. Neither is circulating domestically in the continental U.S. If you’re planning travel to affected areas, mosquito prevention measures like repellent and long sleeves are your best defense.
COVID Variants in Early 2026
COVID-19 hasn’t disappeared, but it’s behaving more like a seasonal virus now. The dominant variants circulating in the U.S. as of mid-February 2026 are a family of lineages called XFG, which together account for roughly 65% of sequenced cases. Another lineage, NB.1.8.1, makes up about 21%. These names change frequently as the virus continues to evolve, but none of the current variants have triggered new public health warnings about increased severity.
Updated vaccines remain the primary tool for reducing your risk of severe COVID illness. For the current flu season, this year’s flu vaccine is trivalent, covering two influenza A strains (H1N1 and H3N2) and one influenza B strain. If you haven’t gotten either vaccine this season, both are still available.
What to Do If You’re Sick Right Now
If you’ve come down with respiratory symptoms, the practical steps are straightforward. Stay home to avoid spreading whatever you have. Test if you can, especially within the first day or two, since that’s when antiviral treatment for both flu and COVID is most effective. Stay hydrated, rest, and monitor your symptoms. Fever, cough, and fatigue that gradually improve over several days are typical for all three major circulating viruses.
Symptoms that warrant more urgent attention include difficulty breathing, chest pain or pressure, confusion, an inability to keep fluids down, or symptoms that improve and then suddenly worsen. These patterns can signal complications like pneumonia regardless of which virus is responsible.