The newest COVID variants circulating right now all descend from the JN.1 lineage, which the WHO still lists as the only official Variant of Interest. The names you’re most likely to encounter are KP.3.1.1, NB.1.8.1, XFG, and BA.3.2, all of which the WHO currently classifies as Variants Under Monitoring. If you’ve seen the nickname “FLiRT” in headlines, that refers to the KP.2 and KP.3 family of subvariants, named after the specific mutations on their spike proteins.
The Variants Circulating Now
COVID hasn’t stopped mutating since Omicron took over in late 2021, but the naming has gotten more confusing because the virus is now branching into many closely related sublineages rather than producing dramatically different variants like Delta or the original Omicron. Here’s a quick breakdown of what’s currently on the WHO’s tracking list:
- JN.1 is the parent lineage and the only variant still classified as a Variant of Interest. It was first sampled in August 2023 and designated in December 2023. Nearly every subvariant circulating today traces back to it.
- KP.3.1.1 (clade 24E) is a descendant of KP.3, first sampled in March 2024. It was one of the dominant strains through late 2024 and into 2025.
- NB.1.8.1 (clade 25B) was first sampled in January 2025 and designated as a Variant Under Monitoring in May 2025. It carries several new spike protein changes compared to JN.1.
- XFG (clade 25C) also appeared in January 2025 and was designated in June 2025. It has a large number of spike mutations, which is why it caught the attention of virus trackers.
- BA.3.2 was first sampled in November 2024 and designated in December 2025. It stands out because it carries a very long list of mutations relative to the original virus, suggesting a significant evolutionary step.
What “FLiRT” Actually Means
You may have heard the term “FLiRT variants” in news coverage. This isn’t an official WHO label. It’s a shorthand nickname based on the technical names of two key mutations on the spike protein: one at position 346 (R346T) and another at position 456 (F456L). The letters F, L, R, and T from those mutation codes spell out “FLiRT.” KP.2 was the first major variant described this way, and KP.3 followed with similar changes.
These two mutations matter because they sit in the part of the spike protein that your antibodies target most effectively. Changes at those positions help the virus slip past immune protection you’ve built up from previous infections or vaccination. Research on antibodies from vaccinated people and those who had recovered from COVID found that the R346T mutation alone was enough to completely block certain antibodies from neutralizing KP.2.
How Current Vaccines Match Up
The 2024-2025 COVID vaccines were designed to target KP.2, a JN.1 descendant. The FDA originally advised manufacturers to build a JN.1-based vaccine, but as KP.2 rose in prevalence, the agency shifted its recommendation to the KP.2 strain specifically. Both Pfizer and Moderna’s updated mRNA shots use this formula.
Because NB.1.8.1, XFG, and the other newer subvariants also descend from JN.1, the current vaccines are expected to offer some cross-protection. That said, each new batch of mutations chips away at how well existing antibodies recognize the virus. This is why vaccine formulas are updated periodically, similar to the annual flu shot.
Symptoms Haven’t Changed Much
The CDC’s current symptom list for COVID remains the same regardless of which subvariant you catch: fever or chills, cough, sore throat, congestion or runny nose, fatigue, muscle aches, headache, and sometimes nausea or diarrhea. Loss of taste or smell is still listed as a possible symptom, though it became less common with Omicron-era strains compared to earlier waves. Shortness of breath remains on the list but is more typical in severe cases.
Symptoms can appear anywhere from 2 to 14 days after exposure and often start mild before potentially worsening. Your vaccination status and history of previous infections both influence how the illness feels. Many people with up-to-date immunity experience something closer to a bad cold.
Do Rapid Tests Still Work?
Home antigen tests are still a valid way to check for COVID, but there’s a catch with timing. The FDA notes that how quickly a test can detect the virus may vary between different variants and different test brands. If you test negative but have symptoms, testing again 24 to 48 hours later improves your chances of catching a true positive. The tests detect a protein on the virus’s outer shell that hasn’t changed as dramatically as the spike protein, which is why they continue to function across variants.
Why the Names Keep Changing
Early in the pandemic, the WHO assigned Greek letters (Alpha, Beta, Delta, Omicron) to major variants that behaved significantly differently from their predecessors. Since Omicron, the virus has continued evolving but hasn’t produced a variant different enough to earn a new Greek letter. Instead, scientists use the Pango lineage system, which is why you see alphanumeric codes like KP.3.1.1 or NB.1.8.1. Each code traces the variant’s family tree back through its parent lineages.
The WHO groups these into two tiers: Variants of Interest (VOIs), which show confirmed changes in transmissibility or immune evasion, and Variants Under Monitoring (VUMs), which have genetic changes worth watching but haven’t yet proven to pose a significantly increased risk. All of the newest names on the list currently fall into the VUM category, with JN.1 remaining the sole VOI as the broad parent lineage.