United States: As the peak summer travel season arrives in the United States, a new variant of COVID-19 has been spreading quickly worldwide and is known as NB.1.8.1 or Nimbus.
More than one-third of COVID cases in the US are now being caused by the highly transmittable omicron subvariant that sparked surges in Asia this spring, according to data.
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Nimbus first appeared in the US in late March through airport screening programs for international travelers.
The new variant, which spreads rapidly, has since been detected in over a dozen states in the United States, and the cases are set to continue increasing, as today.com reported.
May 23 The World Health Organization (WHO) designated NB.1.8.1 as a “variant under monitoring” because it has spread rapidly around the world and has mutations in its spike protein, which could impact its transmissibility.
COVID variant NB.1.8.1 has hit the U.S. Here's what to know about symptoms, new booster vaccine restrictions and more. https://t.co/270FIGM1YD
— CBS News (@CBSNews) May 27, 2025
Naming The name Nimbus was created in late May on X by T. Ryan Gregory, a Canadian evolutionary biologist responsible for other popular COVID variant names, such as the FLiRT strains.
Even though NB.1.8.1 is increasing the percentage of cases in the U.S., the trend of COVID is rather unfortunate.
According to the most recent data provided by the US Centers for Disease Control and Prevention (CDC), test positivity rates stand at 3%, rising only 0.2% in the past week, and COVID hospitalizations are on the decline.
Nationally, the COVID viral activity in wastewater is at the level of low as of June 6, according to CDC data.
This is, however, likely to change in the next few months, according to experts. Since 2020, COVID-19 cases in the US have been rising in the summer, as today.com reported.
There is concern about a potential surge with the occurrence of a mutated new variant, Nimbus.
According to the most recent data provided by the CDC, NB.1.8.1 is estimated to have caused 37 percent of cases in the US during the two weeks ending June 7, a jump over the 15 percent it caused during the previous two weeks. LP.8.1 is the predominant variant, causing 38 percent of the cases.