"Razor blade throat": The "Nimbus" COVID variant sparks concern of summer surge

Yahoo

11-06-2025

Post-pandemic amnesia is a natural reaction, and it's common for misremembering to occur after a pandemic or collective traumatic event occurs. Yet the reality is that SARS-CoV-2, the virus causing COVID-19, is still finding ways to infect people by evolving new mutations, and a new variant has raised concern among virologists that continue to track the virus.
Last month, the World Health Organization labeled the COVID variant NB.1.8.1 a 'variant under monitoring' because it has been surging across Asia and made up 10.7% of global sequences reported as of mid-May. Now, the variant has been detected in the United States, Europe and Canada as well, concerning virus trackers who — for the first time since the Pirola variant began circulating in August 2023 — bestowed upon it a nickname: Nimbus.
Nimbus has recombined genetic material from other strains three times. Although the process of recombination is a natural process of viruses trying to evolve to survive among the population, recombination events are concerning because each time a virus does so, it has the potential to evolve into something that is more infectious or causes more severe disease.
One of these mutations in Nimbus allows it to evade the immunity we have built against the virus from prior infections, so transmissibility might be slightly higher, said Dr. Rajendram Rajnarayanan, of the New York Institute of Technology campus in Jonesboro, Arkansas.
A recent preprint study, not yet peer-reviewed, found that the way this variant binds to cells could make it infect them more efficiently than earlier strains and that it could be easier for this strain to be passed along to someone else. However, there has not been any evidence yet to suggest that Nimbus is linked to more severe illness.
'We haven't seen a big surge in emergency departments due to COVID-related conditions and respiratory things in this term yet,' Rajnarayanan told Salon in a video call. 'We have to wait and watch.'
Recently, many people have been reporting a symptom called 'razor blade throat,' but it's unclear if this is a symptom of COVID or one of the many other viruses circulating. Overall, it is difficult to attribute certain symptoms to variants when there are more than a dozen circulating at a time and testing remains relatively low compared to earlier stages of the pandemic, said Dr. T. Ryan Gregory, an evolutionary and genome biologist at the University of Guelph in Canada.
'That said, we learned from Omicron that high transmissibility can cause as much damage as high per infection virulence, and at this point it is not just acute severity that is of concern, but longer-term impacts of repeated infection,' Gregory told Salon in an email. Such impacts include conditions like "long COVID," in which the symptoms of COVID last for months or years, often disabling patients.Nevertheless, current data shows that most COVID infections in the U.S. are currently caused by the LP.8.1 variant, which descends from Pirola. Both of these strains are technically still in the WHO's Greek letter 'Omicron' family, which now contains thousands of offspring. If there's one thing viruses are good at, it's mutating into new forms that can evade our immunity, whether that's from vaccines or past infections.
In 2023, the WHO decided to only name variants with this system if they were considered a 'variant of concern' and stated that certain action steps should be taken by countries if a variant fell under this classification. However, the agency has not labeled any variants like this since Omicron.
Some argue that some variants have been different enough to warrant a new name, and that not naming variants makes it more difficult to distinguish between the complex alphabet soup of variants that are circulating at any given time.
For example, Pirola, which included the BA.2.86 variant along with its descendants, was about as genetically different from the original Omicron strain as Omicron was from the original 'wild strain' virus from Wuhan, China.
Nevertheless, in the past two years, 'it's largely been the Pirola show,' Gregory said. Current vaccines have been designed to protect against this strain.
So far, Nimbus is not very common in the U.S., but it has been identified in California and has enough mutations in its spike protein that it has a potential to cause waves of illness in other regions — which is in part why it was designated a name. At-home tests should still work to detect this variant, but PCR tests that doctors can order are more accurate. Masking also helps prevent the spread of the virus.
Every year following the start of the COVID pandemic, cases have surged in the summer. Last year's summer surge hit around August and was so intense that vaccines were approved slightly early. Although this year's summer wave hasn't yet started, experts predict we will likely experience another wave this summer. As it stands, variant trackers expect either Nimbus or another variant called XFG to be the dominant strain this time around. Although XFG currently makes up a greater proportion of cases in North America than NB.1.8.1, the latter has been detected in New York and California.
'NB.1.8.1 is a strong candidate for the summer surge,' Rajnarayanan said. 'Yet what we know from previous instances is that it doesn't have to be a single variant that pushes up [to prominence] and sometimes it can be a group of variants … that pick up mutations from each other and recombine.'
The good news is that Nimbus is still similar enough to the Pirola variants that the available vaccines were designed to target. That means they should still be effective, Gregory said. However, concerns have been raised that vaccine access may be limited this fall due to the Food and Drug Administration announcing it would require drugmakers to conduct a new set of clinical trials before approving new vaccines for use. Last month, the FDA also said it will only recommend COVID vaccines for adults 65 and older and those at risk for severe illness. Critics have said this will only make the vaccines less likely to be covered by insurance and less available overall.
On Monday, secretary of the Department of Health and Human Services Robert F. Kennedy announced he was firing the expert panel that advises the Centers for Disease Control responsible for making recommendations on vaccines, further complicating matters.
Paired with updated guidelines from the CDC that drop recommendations for healthy pregnant women and kids to routinely get vaccinated, these changes from the federal government could have a chilling effect that leads fewer people to get vaccinated.
'I'm concerned about accessibility,' Rajnarayanan said, adding that it's not clear if vaccines will be available to people without insurance that aren't included in federal recommendations. 'These kinds of things are still murky and I really want to see clearer guidelines.'
While many people may seem to have forgotten about COVID, people are still routinely hospitalized and killed by the virus. Additionally, each COVID nfection carries a risk of going on to develop long Covid, which continues to debilitate millions of people. As we witnessed when COVID was a full-blown pandemic, emerging viruses can be especially damaging for people with existing conditions like diabetes, obesity and heart disease.
It's important to protect against things like long COVID not only for the well-being of people today but also for our susceptibility to future viruses, Rajnarayanan said.
'In different parts of the world, I've seen funding for continuous surveillance gone down, and not just for surveillance, which is important, but also studying the disease itself,' Rajnarayanan said. 'This is not just about protecting [people] today but also protecting them from any other variant in the future.'