‘Nimbus’ COVID variant causing ‘razor blade throat’ now in Texas. What to know
AI-generated summary reviewed by our newsroom.
- The CDC confirms fewer than 20 NB.1.8.1 cases in U.S. and none in Texas as of this writing
- COVID transmissions have spiked between June and August every year since 2020.
- WHO says current vaccines remain effective against NB.1.8.1 symptoms and severity.
A new variant of COVID has emerged and the virus’ peak season is upon us.
The variant is named NB.1.8.1, or “Nimbus.” The most recent figures available from the CDC showed that 43% of current COVID cases in the U.S. were caused by Nimbus.
The Global Initiative on Sharing All Influenza Data (GISAID) database shows that the variant has popped up in 17 different states, including Texas. Cases are expected to increase, but the WHO categorizes NB.1.8.1 overall risk as low– for now.
Every year since 2020, COVID has spiked between June and August. This summer will likely be no exception, according to John Hopkins Bloomberg School of Public Health.
“Several factors drive summer COVID waves. By mid-to-late summer, many people’s immunity — either from their last vaccination in the fall or from a previous infection—has waned considerably,” according to an August 2024 article from the hospital. “That, combined with the emergence of more transmissible variants, makes the chance of infection more likely.”
Here’s what we know about the new strain and what experts are saying to expect for summer.
About the new COVID variant: NB.1.8.1
NB.1.8.1, or “Numbis,” is a version of the Omicron variant. Since January, It has quickly spread in China and Hong Kong, becoming the dominant strain there. Now, it has been detected in more than 20 countries, including the U.S., India and several European countries.
The World Health Organization says “NB.1.8.1 is designated a SARS-CoV-2 variant derived from the recombinant variant XDV.1.5.1.” They also compare the new strain to LP.8.1, another SARS variant discovered in July 2024 that also poses low risk.
Both these SARS variants are highly contagious, according to the WHO. NB.1.8.1 in particular possesses quite a few new mutations on its spike protein that make it easier to cling to human cells.
Nimbus COVID symptoms
Nimbus variant symptoms are similar to those of other COVID strains, with a notable exception.
People infected with Nimbus are reporting a sore throat so sharp and painful, it’s being compared to swallowing glass, calling it “razor blade throat.” It’s unclear if the “razor blade throat” symptom is more common in people who are up to date on their COVID vaccinations and boosters compared to those who are not, according to ABC News.
The most common COVID symptoms are dry cough and shortness of breath. According to the CDC, all possible COVID symptoms include:
Fever or chills
Cough
Shortness of breath or difficulty breathing
Sore throat
Congestion or runny nose
New loss of taste or smell
Fatigue
Muscle or body aches
Headache
Nausea or vomiting
Diarrhea
Does the COVID vaccine work against NB.1.8.1?
The WHO reports that “currently approved COVID-19 vaccines are expected to remain effective to this variant against symptomatic and severe disease.”
How to prevent COVID
Though you cannot always control contracting an illness, you can still do your best to prevent it.
The CDC recommends the following:
Stay up to date with all COVID vaccines.
Cover your mouth and nose when coughing or sneezing.
Wash hands with soap and water for at least 20 seconds.
Keep frequently touched surfaces clean.
Stay home if you are feeling sick.
Wear a mask.
This story was originally published June 5, 2025 at 5:09 PM.
