As of mid-February 2026, the dominant COVID strain in the United States is XFG, making up about 29% of sequenced cases. It’s joined by several close relatives and one distinct lineage, NB.1.8.1, which accounts for roughly 21%. National wastewater surveillance shows moderate viral activity overall, with the Midwest reporting the highest levels. Here’s what you need to know about the strains circulating right now, the symptoms they cause, and how well current tools hold up against them.
Which Variants Are Circulating
The CDC’s latest Nowcast estimates, covering the two weeks ending February 14, 2026, show a patchwork of related lineages rather than one overwhelming strain. XFG leads at 29%, followed by NB.1.8.1 at 21% and XFG.2.5.1 at 16%. Several other XFG offshoots fill in the rest: XFG.1.1 (9%), XFG.14.1 (7%), and XFG.6 (4%). Smaller shares go to XFZ (5%), PQ.17 (4%), XFV (2%), and XFY (2%).
The World Health Organization currently classifies JN.1 as its sole Variant of Interest, while XFG, NB.1.8.1, KP.3.1.1, and BA.3.2 are listed as Variants Under Monitoring. None of these have triggered a formal Variant of Concern designation, which would signal a major shift in severity or immune escape.
Where Activity Is Highest
Wastewater data for the week ending February 21, 2026, puts the national viral activity level at moderate (3.94 on the CDC’s scale, where anything above 3.4 crosses into moderate territory). But the picture varies sharply by region. The Midwest leads at 5.52, close to the “high” threshold. The Northeast sits at 4.91, the South at 2.96, and the West is lowest at 1.49.
At the state level, Illinois, Mississippi, South Dakota, and West Virginia all show very high wastewater signals. Several states across the Midwest and Northeast, including Indiana, Minnesota, Wisconsin, Connecticut, Delaware, Maine, Maryland, Nebraska, New York, and Rhode Island, register as high. Meanwhile, much of the West Coast and Southwest, including California, Arizona, Oregon, and Florida, remains at very low levels. If you’re in a high-activity state, the odds of encountering the virus in everyday settings are meaningfully greater right now.
Symptoms to Expect
The symptom profile for current variants hasn’t shifted dramatically from what most people experienced during previous Omicron waves. The CDC’s current list includes fever or chills, cough, sore throat, congestion or runny nose, fatigue, muscle aches, headache, shortness of breath, nausea or vomiting, and diarrhea. Loss of taste or smell still appears but is less commonly reported than it was with earlier strains.
Many people describe something that feels like a bad cold or mild flu for the first few days, with fatigue lingering longer. Symptoms can vary depending on whether you’ve been vaccinated or previously infected, with vaccinated individuals tending to report milder and shorter illness.
Incubation Period and Testing Timing
The time from exposure to first symptoms has shortened compared to the original virus. Early pandemic strains averaged about 6.5 days. The Delta variant shortened that to roughly 4.3 days, and Omicron-era variants brought it down further to a median of 3 to 4 days. Current circulating strains, all descendants of Omicron, likely follow a similar 3-to-4-day timeline.
This matters for testing. Home antigen tests still detect current variants, but they’re generally less sensitive than lab-based molecular (PCR) tests, particularly in the first day or two of symptoms. If you test negative early on but feel sick, testing again 24 to 48 hours later improves accuracy. The FDA has noted that some antigen tests may have reduced sensitivity with newer Omicron subvariants, so a single negative result doesn’t rule out infection when symptoms are present.
How Well the Current Vaccine Matches
The 2025-2026 COVID vaccine formula, recommended for use starting in fall 2025, targets the JN.1 lineage, specifically using the LP.8.1 strain. The FDA’s advisory committee chose this composition based on the variants circulating at the time of the decision and manufacturing timelines. Because XFG and NB.1.8.1 are descendants of the JN.1 lineage, the updated vaccine is expected to provide meaningful cross-protection, though exact effectiveness numbers against each sub-lineage are still being evaluated through ongoing surveillance.
This is the same pattern as flu vaccines: the formula is designed months ahead and targets the lineage family most likely to dominate. It won’t be a perfect match for every circulating strain, but vaccination continues to reduce the risk of severe illness and hospitalization.
Long COVID Risk With Current Strains
A large meta-analysis published in Open Forum Infectious Diseases found that infections from pre-Omicron variants (Alpha, Delta) carried about 74% higher odds of developing long COVID compared to Omicron-era infections. Being unvaccinated roughly doubled the risk (odds ratio of 2.09), making it the single strongest risk factor identified across studies. Female sex also increased the odds by about 56%.
This doesn’t mean long COVID has disappeared. It means your baseline risk from a current infection is lower than it would have been in 2021, especially if you’re vaccinated. Some research suggests that vaccination narrows the gap between variants even further, with one study finding that severe fatigue and multi-symptom long COVID were no longer significantly different across variants once vaccination status was accounted for.
Antiviral Treatment Still Works
Paxlovid, the oral antiviral prescribed for people at higher risk of severe COVID, remains effective against Omicron-lineage variants. It suppresses viral replication by over 99% per day when taken as directed, which is why starting it within the first five days of symptoms matters. Modeling studies estimate that treating even 20% of symptomatic patients with the drug could prevent hundreds of thousands of hospitalizations during a transmission wave.
If you’re over 65, immunocompromised, or have conditions like diabetes, heart disease, or chronic lung disease, asking about antiviral treatment early in your illness is worth doing. The drug works best when started promptly, and waiting for symptoms to worsen reduces its benefit.