Everything we know about new Covid variants 'Stratus' and 'Nimbus' that are sweeping the US

As Covid makes a resurgence in the US, there's a few things that you should be aware of.

Five years ago, coronavirus brought the world to a standstill. Millions of people around the world were furloughed, schools were shut, and even our beloved local cafes were prevented from trading.

Mask wearing was compulsory, hand sanitizer was a must, and 'social distancing' became the norm - as did 'lockdowns'.

Three years later, the World Health Organization (WHO) declared the end of the Covid-19 pandemic.

Just as our lives have returned to normality, two new Covid variants have been detected in America, making their way across the country, and each with rather unusual symptoms.

Here is everything that we know about these new strains of the virus, which have been dubbed 'Stratus' and 'Nimbus'.

President Donald Trump pictured wearing a mask during his first term in 2020 (Chris Kleponis/Polaris/Bloomberg via Getty Images)

What is the Covid variant Nimbus?

It sounds like something straight out of Harry Potter, but unfortunately we're not talking about the mythical flying broomstick, the 'Nimbus 2000'.

The virus, which is known in the science background as NB.1.8.1, was first detected in China in January, before making its way out of the continent and across Europe, Australia, and North America.

This latest version of the virus has picked up some genetic tweaks that make it cling to human cells even more effectively, meaning it’s really good at spreading - and fast.

While experts are still keeping an eye on what exactly this means for symptoms and vaccine resistance, one thing’s clear - it is no longer going unnoticed.

Nimbus symptoms

If you catch the Covid subvariant, the chances are the symptoms will feel familiar - mostly mild and similar to what you'd expect from a standard cold or flu - but there’s one thing that’s been standing out for a lot of people.

That is a seriously nasty sore throat - we’re talking a sharp, stabbing pain, especially during the early days of infection, and it’s been enough to make swallowing feel like a full-body workout.

Other common symptoms include feeling totally wiped out, a lingering cough, stuffy or runny nose, fever, muscle aches, and sneezing fits.

Some people have also reported stomach-related issues like nausea or even diarrhea, though that’s been less common.

Overall, it’s not exactly pleasant, but for most, it’s not as intense as earlier waves of the virus. Still, probably best to take it easy if you start feeling rough.

Nimbus is a particular nasty variant of Covid, with patients complaining of how painful it can be (Getty stock)

What is the Covid variant Stratus?

Stratus - otherwise known by its scientific name 'XFG' - first cropped up in Southeast Asia also in January, and by June had spread to a 38 countries.

It is being investigated by the WHO, and is being monitored closely.

While Nimbus spreads much quicker and has a signature symptom - 'razor blade' sore throat, Stratus showcases 'marginal additional immune evasion', compared to that of Nimbus, according to the WHO.

All that means is that it can evade the immune system better, making it harder to be recognized.

If someone hasn't received Covid vaccinations then it could make it much harder to fight off.

Stratus symptoms

Again, like Covid-19 and Nimbus, symptoms are similar to a cold or a flu.

Common symptoms include a persistent, dry cough; a fever; and fatigue.

While some people have also complained of having a sore throat, a tight chest, brain fog/trouble concentrating, an upset stomach/loss of appetite, body aches and headaches.

Loss of taste or smell has also been reported but that is much less common.

The Covid variant 'Stratus' evades the immune system much better than Nimbus, and spreads rapidly (Getty stock)

What have the experts said?

According to the CDC, nationwide Covid wastewater levels, which are used to measure community spread of the infection, sit at 'moderate', though it acknowledges at least four US states have 'very high' levels.

Doctor Aaron Glatt, an infectious disease expert from Mount Sinai Hospital in New York, told Today.com that 'severe pain' is a prevailing problem, with patients feeling 'as if their throat is covered with razor blades'.

He added: "While not specific to Covid-19, this expression has been used to describe sore throat symptoms in some patients with the most recent Covid-19 variant."

Others are also warning about declining Covid vaccination rates being behind a possible increase in cases, with a CDC panel voting against recommending the shots for 'individual decision-making'.

Yet an infectious disease specialist, who worked as New York City's chief medical officer during the first wave of the pandemic, warns Coronavirus is 'clearly on the rise again'.

Doctor Tyler Evans told The Daily Mail: "While we’re in a much better place than in 2020, rising transmission still poses a risk to those with underlying conditions or limited access to care. Concern should lead to preparedness, but not panic."

Nimbus patients have reportedly likened its sore throat symptom to the pain of having swallowed razor blades (Getty stock)

He added: "The dominant strain in the US right now is an Omicron subvariant called Nimbus (NB.1.8.1). It spreads quickly but is not more severe than earlier forms."

While it is no more dangerous than its predecessors, Dr Evans said it 'can still be dangerous for older adults, people with chronic conditions, and those with weakened immune systems.'

Doctor Laura Malone, director of the Pediatric Post-Covid-19 Rehabilitation Clinic at Kennedy Krieger Institute in Baltimore, added to the New York Times that even mild infections can pose a long-lasting effect, like long Covid.

"Just because you got through your first infection and didn’t develop long Covid, it’s not that you are completely out of the woods," she explained.

The good news is that Covid wastewater levels are showing signs of slowing down, declining in the week of September 13, though Nevada, Connecticut, Utah and Delaware, meanwhile, are currently recording 'very high' levels.