New COVID Variant ‘Nimbus’ Sparks Concerns in U.S.

June 19, 2025 – WASHINGTON, D.C. — A new COVID-19 variant named NB.1.8.1, informally referred to as ‘Nimbus,’ is increasing its presence in the United States, accounting for over one-third of COVID cases as of June 7, according to the Centers for Disease Control and Prevention (CDC).

This strain, a descendant of the Omicron variant, was first detected in the U.S. in late March through airport screenings. Since then, it has been reported in more than 14 states. Health officials have linked it to outbreaks in parts of Asia and reported that it appears to be more transmissible, but not necessarily more severe.

Dr. Marc Siegel, Fox News’ senior medical analyst, explained that Nimbus has been associated with severe sore throats, with patients describing the pain as akin to “swallowing razor blades.” He noted that while many COVID variants present with different symptoms, sore throat has become increasingly common with Nimbus.

Data shows that Nimbus accounted for approximately 37% of COVID cases in the U.S. during a recent two-week period, indicating a rapid rise from earlier reports. The CDC has marked this variant for monitoring due to its concerning spike protein mutations, which may enhance its ability to spread.

As the summer travel season approaches, health experts are urging caution. Dr. Albert Ko, a public health professor at Yale, mentioned, “It’s hard to predict whether this variant will trigger a significant wave, but historical trends of summer spikes have been observed since 2020.”

Symptoms associated with Nimbus are similar to those of previous strains, including coughing, fatigue, and sore throat. Experts are concerned that waning immunity among the population could facilitate another surge.

Public health officials emphasize the importance of vaccination. The WHO reported that the current vaccines are expected to remain effective against the Nimbus variant, and health officials recommend that individuals, especially those in high-risk groups, consider getting vaccinated this summer.

As the situation evolves, officials continue to monitor the developments closely, urging the public to remain vigilant and prioritize health and safety measures.