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NB.1.81 Covid variant spreads to US: What are the symptoms and should you be worried?

The highly infectious NB.1.81 Covid variant has been detected in the US, including in New York City, the Centers for Disease Control and Prevention has said.

Published on: May 28, 2025, 05:55:45 IST
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A new, highly infectious strain of Covid-19 has been detected in the United States, including in New York City, the Centers for Disease Control and Prevention has confirmed. The new NB.1.81 variant led to a spike in hospitalizations in China before being detected in the US.

NB.1.81 Covid variant spreads to US: What are the symptoms and should you be worried? (Unsplash - representational image)
NB.1.81 Covid variant spreads to US: What are the symptoms and should you be worried? (Unsplash - representational image)

The new variant was first found in the US in late March and early April. It was detected among international travelers who arrived at airports in California, Washington State, Virginia and New York City. Some cases were also found in Ohio, Rhode Island and Hawaii.

According to the CDC, there are not many cases in the US yet and thus they cannot be properly tracked in the agency’s variant estimates. However, experts have warned that the virus’ run in China indicates that it spreads rapidly, in fact, quicker than other dominant strains of the infection.

“CDC is aware of reported cases of COVID-19 NB.1.8.1 in China and is in regular contact with international partners. There have been fewer than 20 sequences of NB.1.8.1 in the U.S. baseline surveillance data to date, so it has not met the threshold for inclusion in the COVID Data Tracker dashboard,” a CDC spokesperson told Fortune. “We monitor all SARS-CoV-2 sequences, and if it increases in proportion, it will appear on the Data Tracker dashboard.”

Dr. William Schaffner, Vanderbilt University School of Medicine professor of medicine and preventive medicine, said that the new variant is “kind of scattered about the U.S. at the moment, in small numbers,” and appears to be a variant of the Omicron family. “So it’s not a dangerous new mutant, but the latest cousin,” he added.

What are the symptoms of the NB.1.8.1 variant and should you be worried?

Schaffner told the outlet that the new variant does not have any unique characteristics and causes only mild symptoms, including congestion or a runny nose, cough, fatigue, headache, body aches, and fever or chills.

Schaffner noted that even though the variant is contagious and will possibly continue to spread, more than 95% of the US population has either had COVID or the vaccine or both, so now they have “extraordinary population immunity.”

“Now, this is not to say that Omicron is trivial, because there are on the order of 200 to 300 deaths that are occurring weekly, still due to COVID infection,” Shaffner said. “Of course, those are in highly vulnerable populations—older persons and people with chronic underlying medical conditions—by and large.”

Explaining why it is important to track the strains, Schaffner noted that “we want to be sure that the vaccines we offer are going to provide reasonable protection against severe disease caused by these various strains.” It is currently believed that the vaccines on offer are going to protect against the new strain.

  • Sumanti Sen
    ABOUT THE AUTHOR
    Sumanti Sen

    Sumanti Sen covers everything that’s happening in the US, from politics to entertainment, but her expertise lies in covering crime news. She has comprehensively chronicled the Idaho student murders, the Laken Riley and Iryna Zarutska cases, and the killing of Charlie Kirk, among other incidents. Over the years, she has interviewed several victims/families of victims of crimes seeking justice. She digs up stories that might otherwise remain unheard, and does her bit to ensure that victims and survivors’ voices are heard. Sumanti’s many years of experience also include interviews with Hamas attack survivors and mental health experts, among others. Her coverage of the October 7 Hamas attack on Israel and interviews with survivors of the tragedy, coupled with her other works including the Titan submersible coverage, earned her the Digi Journo of the Quarter award during her first year at Hindustan Times. Sumanti actively tracks missing person cases in the United States, and peruses Reddit and other social media platforms to bring to light cases that frequently elude public attention. She has extensively covered the disappearances of Nancy Guthrie, Thomas Medlin, Beau Mann, and Sudiksha Konanki, among others. When not at work, you will either find her with her novels, or with her beloved rescue pooches.Read More

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