So, everyone’s talking about "Stratus" again. If you’ve been scrolling through your feed lately and seeing mentions of Stratus XFG, you might be wondering if we're back in 2020. We aren't. But California is definitely seeing a weird little surge right now, and honestly, it’s mostly thanks to this specific subvariant.
It's officially called XFG, but the "Stratus" nickname stuck because, well, it sounds a bit more dramatic.
In California, the numbers have been doing that annoying zig-zag. For a while, things were quiet. Then, wastewater data from places like San Francisco, Sacramento, and even Kern County started showing these massive spikes in the XFG signature. Basically, the virus is still here, it’s just wearing a new outfit.
What is Stratus XFG anyway?
Technically, XFG is what scientists call a recombinant. That's just a fancy way of saying two different Omicron versions—specifically LF.7 and LP.8.1.2—met inside someone’s body, swapped some genetic code, and created a "mashup" variant. It’s like a remix of a song you’ve already heard way too many times.
What makes it different? It’s incredibly "sticky."
Because of its specific mutations, Stratus XFG binds tighter to human cells than some of its predecessors. This is why it spread so fast across the West Coast. In late 2025, it went from being a tiny blip to representing over 80% of cases in some California counties in just a few weeks. It's fast.
But here is the good news: just because it spreads faster doesn't mean it’s meaner. Most doctors, including the folks at UCSF and the CDPH (California Department of Public Health), say they aren't seeing a huge jump in "severe" disease. It’s more of a "ruin your week" kind of sick rather than a "go to the ER" kind of sick for most healthy people.
The California Situation: A Tale of Two Tides
California is big. Really big. So, the stratus xfg covid-19 california cases aren't hitting everyone the same way.
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In Southern California—specifically Los Angeles and Orange Counties—test positivity rates hit a peak of around 14% earlier this winter. That's high. You've probably noticed more people calling out of work or kids missing school with "the crud."
Up north, the Bay Area has been relying heavily on wastewater surveillance. Stanford’s WastewaterSCAN program has been the real MVP here. They caught the Stratus surge long before the clinical tests showed it, because, let's be real, almost nobody goes to a doctor for a PCR test anymore. We just use those little orange boxes at home.
Why California?
- Travel Hubs: SFO and LAX are basically variant front doors.
- School Cycles: The timing of the Stratus surge lined up perfectly with kids heading back to classrooms.
- Waning Immunity: A lot of people skipped the 2025-2026 booster because they were just... done.
The "Razor-Blade" Throat and Other Symptoms
If you catch Stratus XFG, you’ll likely know it by your throat.
Many patients in California are reporting a sore throat that feels like swallowing glass. Dr. Peter Chin-Hong at UCSF mentioned this "razor-blade" sensation is pretty common with the recent Omicron lineages. It’s brutal for a couple of days, then it usually settles into a standard cold.
Here is the weird part: some people are getting hoarse. Like, "lost my voice" hoarse. While not everyone gets it, it’s a symptom that keeps popping up in clinical reports specifically tied to XFG.
You might also deal with:
- Congestion: The kind where you can’t breathe through your nose for three days.
- Fatigue: Feeling like you got hit by a truck, even if you don't have a high fever.
- GI Issues: Nausea or a bit of a stomach bug vibe is actually more common with Stratus than it was with some of the earlier variants.
Do the tests and vaccines still work?
Yes. Mostly.
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The at-home rapid antigen tests we all have shoved in our junk drawers still pick up Stratus XFG. However, because this variant is so good at hiding from the immune system initially, you might test negative on Day 1 of symptoms. If you feel like garbage, wait 24 to 48 hours and test again.
As for the vaccines, the 2025-2026 formula was designed to target the LP.8.1 lineage. Since Stratus (XFG) is a direct relative of that, the shot still provides solid protection against the "scary" stuff—hospitalization and major lung issues.
What most people get wrong about Stratus
There’s a lot of noise on social media saying this is a "new virus" or that it’s bypassing all immunity.
It’s not a new virus. It’s still SARS-CoV-2. And while it is better at infecting people who have been vaccinated or previously infected (that's called immune escape), your "immune memory" still matters. Your body recognizes the core of the virus, which is why we aren't seeing the same level of intensive care admissions we saw back in 2021.
Also, it's worth mentioning the political side of things. In 2025, federal policy shifts caused some delays in vaccine rollouts. This created a bit of a gap in protection for vulnerable Californians, which gave Stratus a perfect window to jump from person to person.
Navigating the surge: Actionable steps
If you're in California and the "Stratus" wave is hitting your neighborhood, you don't need to panic, but you should probably have a plan. Honestly, it’s just common sense at this point.
Check your kit.
Make sure you have a fresh box of tests. If yours expired in 2024, they might still work, but the "control" line might be wonky. It's better to spend the ten bucks now than to be driving to CVS with a 102-degree fever.
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Masking (When it makes sense).
Look, nobody wants to wear a mask forever. But if you’re heading onto a packed BART train or a flight out of LAX, an N95 is still the best way to avoid a "razor-blade" throat.
Wait to visit Grandma.
If you have a "sniffle" or a "scratchy throat," just stay home for a few days. Stratus is super contagious, and while it might be a minor cold for you, it can still be a big deal for people over 65 or those with compromised systems.
Hydrate for the throat.
If you do get the XFG sore throat, standard lozenges won't do much. Warm salt water gargles and ibuprofen are the real winners for that specific inflammation.
The reality of stratus xfg covid-19 california cases is that we are in a new phase of the "forever virus." It’s less of a crisis and more of a recurring nuisance. California’s robust wastewater tracking means we usually see these waves coming before they hit our offices and schools.
Stay informed by checking the CDPH respiratory virus dashboard, which is updated every Friday. It'll tell you exactly how high the levels are in your specific county so you can decide whether to go to that crowded concert or stay in and watch a movie instead.
To stay ahead of the current wave, you can check your local California county's wastewater levels through the WastewaterSCAN dashboard to see if Stratus XFG is peaking in your specific zip code.