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clock-iconPUBLISHEDJuly 15, 2025
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Stratus: What Are The Symptoms Of The Latest COVID-19 Subvariant To Spread Around The World?

Stratus has joined Nimbus on the global monitoring list.

Laura Simmons headshot

Laura Simmons

Laura Simmons headshot

Laura Simmons

Health & Medicine Editor

Laura holds a Master's in Experimental Neuroscience and a Bachelor's in Biology from Imperial College London. Her areas of expertise include health, medicine, psychology, and neuroscience.

Health & Medicine Editor

Laura holds a Master's in Experimental Neuroscience and a Bachelor's in Biology from Imperial College London. Her areas of expertise include health, medicine, psychology, and neuroscience.View full profile

Laura holds a Master's in Experimental Neuroscience and a Bachelor's in Biology from Imperial College London. Her areas of expertise include health, medicine, psychology, and neuroscience.

View full profile
EditedbyJohannes Van Zijl

Johannes holds an MSci in Neuroscience from King’s College London, where he worked on projects involving Alzheimer’s disease and Fragile X syndrome.

blue world map with lots of charts and graphs, with red virus particles to indicate monitoring spread of a virus around the world

The global community is continuing to monitor the evolution of SARS-CoV-2.

Image credit: Summit Art Creations/Shutterstock.com


We know, we know – it’s only been about a month since we introduced you to the Nimbus variant of COVID-19, but there’s yet another new variant we think you should know about. Sticking with the cloud theme, this one’s called Stratus, or more officially XFG, and the World Health Organization (WHO) is officially monitoring its progress.

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As Professor of Infectious Diseases and Microbiology Paul Griffin explains in a recent piece for The Conversation, Stratus is a recombinant variant. This means it arose when two other variants, LF.7 and LP.8.1.2, shared genetic material. 

According to Gavi, Stratus was first detected in Canada before spreading across the globe.

Like Nimbus, and the other recent variants before it, Stratus is a subvariant of the Omicron lineage. In fact, there are now over 1,000 of these sublineages. Nicknames have been proposed by researchers and citizen scientists to help differentiate between some of them. We went through a phase of using characters and creatures from Greek mythology, like Kraken; now, we’ve moved on to meteorological terms.

But whatever you call them, it’s important to remember that all these subvariants are members of the same big, complicated virus clan.

“So far, these sublineages of Omicron have much in common: they are all highly transmissible, replicate in the upper respiratory tract and tend to cause less severe disease compared to previous variants of concern, and they all have mutations that make them escape built-up immunity more easily,” explains the Memorial Sloan Kettering Cancer Center.

“This means that they are similar in their impact on public health, and the response that is needed to deal with them.”

For people infected with the Stratus variant, the symptoms are likely to be broadly the same as we’ve seen with other Omicron subvariants. That means the familiar constellation of cough, congestion, fatigue, headache, and sometimes a fever. Some people have also experienced gastrointestinal symptoms.

However, each time we get one of these new lineages it seems there are one or two symptoms that particularly catch people’s attention. With Nimbus, it was the “razor-blade throat” – an especially painful sore throat. For Stratus, we’re sticking to the same bodily region.

“One of the most noticeable symptoms of the Stratus variant is hoarseness, which includes a scratchy or raspy voice,” GP Dr Kaywaan Khan told the Independent.

There’s no empirical evidence from studies that these symptoms are more common with either of these variants, but this is what people have been reporting when seeing their doctors.

As of June 27, there were three COVID-19 “variants under monitoring”, according to the European Centre for Disease Prevention and Control: Nimbus, Stratus, and LP.8.1. This designation means that the WHO is reviewing the global epidemiology of each variant and tracking their spread around the world. The next level up would be a variant of interest, and then a variant of concern (VOC). Currently, no circulating variants fit the VOC criteria.

As best as scientists can tell, the current COVID-19 vaccines should still be effective against the latest variants, although they may have some ability to evade prior immunity. For protection against severe illness, vaccines remain the number one tool we have – so if you think you might be due for a booster, and want to check your eligibility, talk with your doctor or pharmacist.


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