What to know about COVID variant NB.1.8.1 causing 'razor blade throat'

Yahoo

19-06-2025

A newer COVID-19 variant may be causing a severe sore throat in some people who contract the infection.
The variant, known as NB.1.8.1, has been nicknamed by some as "razor blade throat" due to the painful symptom.
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Data from the open global genome sequencing database GISAID shows the new variant has been detected in several states, including New York, Illinois, Texas and California.
Public health experts told ABC News there is no cause for serious concern yet because the virus does not appear to be more severe than previous variants and there are steps that can be taken to protect yourself.
NB.1.8.1 derives from the recombinant variant XVD.1.5.1, which is a descendant of the omicron variant.
The first sample of NB.1.8.1 was collected on Jan. 22, according to the World Health Organization (WHO). It was first detected in China and other parts of Asia before spreading to Europe.
It was designated as a "variant under monitoring" by the WHO, meaning it may require prioritized attention and monitoring but is not as serious as a "variant of interest" or a "variant of concern."
As of the week ending June 7, NB.1.8.1 is the second most dominant variant in the U.S., accounting for an estimated 37% of cases, according to the Centers for Disease Control and Prevention (CDC).
The virus appears to be more transmissible because there appear to be changes to the spike protein, which is what the virus uses to attach to and infect cells, said Dr. Peter Chin-Hong, a professor of medicine and infectious disease specialist at the University of California, San Francisco.
It also seems to attach more easily to ACE2 receptors, which are proteins found on the surface of cells and how the virus that causes COVID enters cells, he told ABC News.
NB.1.8.1 doesn't yet appear to be causing increases in cases or in hospitalizations with rates remaining "stable" so far, according to Chin-Hong.
The variant has also been called "Nimbus," which appears to have been coined on X by T. Ryan Gregory, a Canadian professor of evolutionary biology.
"Nimbus is a catchy, quick name, and it also includes an 'N' and a 'B' from the lineage, which is NB.1.8.1. So it's easier for people to be able to say these monikers for COVID, rather than remember the actual lineage," said Dr. Alok Potel, a pediatrician at Stanford Children's Health and an ABC News contributor.
"But I think it's important also because it keeps people paying attention to new COVID variants that can be different in terms of infectivity and in terms of spread," he added.
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Experts said they are not sure if the painful sore throat is just a symptom that people are talking about or a distinctive symptom of this variant.
It's also unclear if the "razor blade throat" is more common in those who are more up to date on vaccination compared to those who are not up to date.
"I think it's certainly amongst the spectrum of symptoms that you can get, and we know that sore throat is reported by about 70% of patients now with COVID, so it's not unusual, and like with everything in medicine, there's always a spectrum," Chin-Hong said.
There is currently no evidence that NB.1.8.1. causes more severe disease or is more likely to cause hospitalization, according to Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University Medical Center in Nashville,
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"But of course, there are people in high-risk groups that are still at risk of being hospitalized should they become infected," he told ABC News.
There are no other symptoms outlined that are specific to NB.1.8.1 by the CDC.
Symptoms listed by the health agency still include sore throat, cough, fever, chills, shortness of breath, difficulty breathing, congestion, runny nose, loss of taste or smell, fatigue, muscle aches, body aches, headache, nausea, vomiting or diarrhea.
The experts recommend that high-risk Americans receive a vaccine twice a year as recommended by the CDC.
The CDC also currently recommends most adults aged 18 and older receive an updated 2024-2025 vaccine and that parents of children between ages 6 months to 17 years discuss the benefits of vaccination with a health care provider.
COVID-19 also tends to spike in the late summer and early fall, so people should consider opening windows to increase ventilation, wearing a mask in certain situations and avoiding crowded areas, Schaffner said.
"Time to stream a movie, as I like to say, rather than going to the movies," he added.
Patel said it's important to practice good hygiene such as proper hand-washing and covering your mouth when coughing or sneezing.
He also recommended that people test if they are symptomatic and said over-the-counter rapid at-home tests work.
"Getting infected with COVID and other infectious diseases is not necessarily life or death, but it can still be very debilitating." Patel said. "It can cause people to miss work, to spread the virus, to get people who are higher risk sick and there's still an untold amount of people who have long COVID."
He added, "So, we don't want to look at COVID as just another common cold, because there's still so much we're learning about it, and there's still so many possibilities with this virus continuing to mutate, if we let it."