What To Know About the New NB.1.8.1 Covid Variant. And Whether You Should Worry.

(Katie Couric Media, Tess Bonn) — It’s more contagious, flying under the radar, and already in the U.S. — meet NB.1.8.1, the latest Covid variant. It hasn’t sparked major outbreaks yet, but experts warn this strain is quietly spreading and may be more transmissible than earlier versions.

Scientists and health officials are closely monitoring the evolution of NB.1.8.1 to compare its characteristics with those of earlier strains, including whether it causes more severe illness and how well current vaccines will protect against it. Early surges in places like China, along with detections in several U.S. states, suggest the variant is slowly gaining ground.

Wondering what this means for you? From symptoms to prevention, here’s a look at everything you need to know to stay safe as the virus continues to evolve.

What is the NB.1.8.1 Covid variant?

NB.1.8.1, a spinoff of the Omicron strain, was first identified in January 2025 and has been steadily spreading since. It evolved from XDV.1.5.1 and is now on the World Health Organization’s radar as a “variant under monitoring” due to its growing global presence.

The earliest surge tied to NB.1.8.1 was reported in China, but it didn’t take long to spread. By late March and early April, U.S. health officials detected it in travelers arriving at California, Washington, Virginia, and New York airports. Additional cases have since been reported in other states, signaling a broader reach. The good news? Numbers remain low. As of now, NB.1.8.1 accounts for fewer than 20 reported cases nationwide, according to USA Today.

What are the symptoms of NB.1.8.1?

While the CDC hasn’t outlined specific symptoms in the NB.1.8.1. variant, experts agree that they mirror those of earlier Covid-19 variants. This includes:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Sore throat
  • Congestion or a runny nose
  • New loss of taste or smell
  • Fatigue
  • Muscle or body aches
  • Headache
  • Nausea or vomiting

Is the new Covid variant more contagious?

Health officials in Hong Kong say NB.1.8.1 doesn’t appear to cause more severe illness than previous strains. What sets it apart, though, is how quickly it spreads. The variant’s tighter binding to human cells is what makes it more transmissible, according to microbiology professor Subhash Verma, Ph.D., from the University of Nevada, Reno, who spoke with CBS.

Another factor driving the surge in places like China could be the timing. Case numbers often rise during the summer months — and this year appears to be no different.

Do the current Covid vaccines protect against this new variant?

The World Health Organization says the current Covid vaccines should still protect against the NB.1.8.1 variant. But there’s a catch: Getting boosters might become more difficult. The Trump administration plans to limit booster shots mainly to older adults and those with certain health conditions. And Health and Human Services Secretary Robert F. Kennedy Jr. just announced that the CDC will no longer recommend routine Covid shots for healthy kids and pregnant women, even though pregnancy remains a high-risk factor for severe complications.

Alongside vaccination, practicing good hygiene, such as thorough handwashing and covering your mouth when coughing or sneezing, remains crucial. And if you’re going to be out in public, it might be worth dusting off that pack of N95 masks you thought you’d never need again. Staying informed and taking simple precautions can go a long way in keeping you and those around you safe.