A croaky voice and a sharp, ‘razor blade’ sore throat are emerging as tell-tale signs of the latest Covid variants now sweeping the US. 

The strains, XFB, called Stratus, and NB.1.8.1, referred to as Nimbus, are responsible for a rise in infections, with a noticeable increase in cases, especially in the northeast over recent weeks.

Across the US, Covid levels in wastewater—which help gauge virus spread in communities—are ‘moderate’ according to the CDC. However, four states report ‘very high’ levels, and the northeastern region is seeing an uptick.

Dr. Aaron Glatt, an infectious disease specialist at Mount Sinai hospital in New York, mentioned on Today.com that patients are experiencing ‘severe pain, as though their throat feels like it’s lined 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.’

While many experts urge Covid vaccination to prevent infection, they warn that confusion over who is eligible for the Covid vaccine could lead to declining vaccination rates and an increase in Covid cases. 

Officials placed more restrictions on Covid vaccines, with a CDC vaccine panel voting against recommending the shots in favor of ‘individual decision-making.’

Dr Tyler Evans, an infectious diseases expert who was New York City’s chief medical officer during the pandemic’s first wave, told Daily Mail: ‘Covid activity is clearly on the rise again. 

‘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.’

Some have reported a sharp, razor-like sore throat is a distinct sign you’re infected with one of the new Covid variants, amid a rise in cases

Dr Evans 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. It can still be dangerous for older adults, people with chronic conditions, and those with weakened immune systems.’

The new strains can also cause more familiar Covid complaints such as headaches, coughing, fatigue and a runny or blocked nose.

Experts stress they are no more dangerous than earlier versions, but genetic mutations mean they spread more easily.

However, Dr Laura Malone, director of the Pediatric Post-Covid-19 Rehabilitation Clinic at Kennedy Krieger Institute in Baltimore, told The New York Times just because an infection is mild or you recover well, doesn’t mean that lasting effects can’t happen, including 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 said. 

The CDC says that it receives little data on Covid variants from the states every year, leading it to have ‘low confidence’ in the estimates, but it warns that the variant is likely causing an increasing proportion of infections.

The agency’s wastewater estimates are based on reports from hundreds of sites across the US that analyze the water for signs of Covid.

An increase or decrease indicates more or fewer people, respectively, are shedding the virus, suggesting infections are rising or falling.

Nationally, Covid wastewater levels began rising at the end of August and peaked through mid September. They’ve been on the decline since the week of September 13, but regionally, other parts of the US are seeing an increase.

Nevada, Utah, Delaware and Connecticut are all recording ‘very high’ levels.

XFG was first detected in January in Southeast Asia and was found in the US two months later.

In May, it accounted for just three percent of Covid infections in the US. But as of September 9, it made up 80 percent of US Covid cases.

The above map shows Covid wastewater levels in the US

In the UK, the Health Security Agency (UKHSA) said positivity had risen from 7.6 to 8.4 percent in just a week, while Covid hospital admissions increased from two to 2.73 per 100,000. 

The UKHSA advises anyone with symptoms to stay at home if possible and avoid contact with vulnerable people. Those who must go out are urged to wear a face covering.

It advised: ‘If you have symptoms of a respiratory infection, such as Covid-19, and you have a high temperature or do not feel well enough to go to work or carry out normal activities, you should avoid contact with vulnerable people and stay at home if possible.’

People over 75, those with weakened immune systems and care home residents are eligible for the winter Covid booster, available on the NHS app, online, or at walk-in centers.

In the UK, health officials have launched a winter vaccination drive, urging millions to come forward for Covid and flu vaccines as hospitalizations creep up.

Pregnant women and children are also invited for vaccination, and toddlers can this year get a flu spray at community pharmacies. 

The rise in cases comes just days after a controversial South Korean study claimed Covid vaccines ‘might raise the risk of cancer’. 

Published in Biomarker Research, it failed to explain how the jabs could trigger the disease.

Experts dismissed the findings as ‘superficially alarming’, warning the conclusions were hugely overblown. Scientists have repeatedly said there is no credible evidence that Covid vaccines interfere with tumor suppressors or fuel cancer growth.