The Spread of Nimbus and Stratus COVID Variants in the U.S.
Summer is typically a time for beach trips and backyard barbecues, but it also brings a rise in Covid cases. The latest report from the CDC indicates that infections, especially those associated with the Nimbus and Stratus variants, are on the rise or likely increasing in at least 26 states and Washington, D.C. Emergency room visits for young children have reached their highest levels since March.
While seasonal spikes are not uncommon, medical experts emphasize the importance of not overlooking them. Dr. Jon LaPook highlighted the pattern of a winter spike followed by a summer spike, noting that the number of deaths and hospitalizations tends to decrease gradually each season, which is positive news.
What is the NB.1.8.1 or Nimbus variant?
A new Covid variant known as NB.1.8.1, or “Nimbus,” has gained attention for causing a severe sore throat likened to feeling lined with razor blades. This variant, identified in January 2025, originated from XDV.1.5.1 and is now being monitored by the World Health Organization due to its increasing global presence.
The initial surge of NB.1.8.1 was seen in China, but it quickly spread to other countries, including the U.S. Health officials in the U.S. detected cases in travelers arriving at airports in California, Washington, Virginia, and New York by late March and early April. The variant has since been reported in additional states, indicating its wider spread. Symptoms of this strain include a severe sore throat, congestion, fatigue, fever, and muscle aches.
What about the Stratus variant?
Similarly, Stratus is a subvariant of Omicron that has been designated as a “variant under monitoring” by the World Health Organization. This variant, first detected in Canada in January, has spread to numerous countries, accounting for about 22 to 23 percent of global Covid cases. Notable symptoms associated with Stratus infections include hoarseness, dry coughs, sore throats, fever, muscle aches, and fatigue.
States with Growing Covid Cases:
– Arkansas
– Hawaii
– Illinois
– Iowa
– Kentucky
– North Carolina
– Ohio
– Pennsylvania
– Texas
– Virginia
Places where Covid Cases are “Likely Growing”:
– Alaska
– California
– Delaware
– District Of Columbia
– Georgia
– Indiana
– Maine
– Maryland
– Massachusetts
– Michigan
– Mississippi
– New Jersey
– New York
– Oklahoma
– South Carolina
– Tennessee
– Wisconsin
Are the Latest Covid Variants More Contagious?
Both NB.1.8.1 and Stratus variants appear to be more transmissible than earlier variants, with Stratus showing a particularly strong ability to spread in both lab studies and real-world scenarios. Although these variants are more contagious, there is no evidence to suggest that
COVID infections may also have seasonal patterns, with cases often increasing in the summer. This year seems to be following that trend, particularly in countries like China. Do the current COVID vaccines provide protection against these new variants? The World Health Organization (WHO) states that the existing COVID vaccines should still offer protection against the NB.1.8.1 and Stratus variants. However, there is a caveat: obtaining a booster shot may not be as straightforward as it once was. The Food and Drug Administration (FDA) has restricted the updated boosters to individuals aged 65 and older and those with specific health conditions. In May, Health and Human Services Secretary Robert F. Kennedy Jr. announced the cessation of routine COVID vaccine recommendations for healthy children and pregnant women, despite pregnancy being a high-risk factor for severe complications. Nonetheless, the Centers for Disease Control and Prevention (CDC) has not completely ruled out vaccination for these groups. Instead, it now promotes “shared clinical decision-making,” meaning that shots are still available if individuals (or parents) opt for them in consultation with a healthcare provider. In addition to vaccination, adhering to basic preventive measures is crucial: maintain regular handwashing, cover your coughs and sneezes, and consider wearing N95 masks in crowded indoor settings. These simple steps can significantly contribute to keeping yourself and your community safer. This article was originally published on Katie Couric Media, discussing the spread of the Nimbus and Stratus COVID variants in the United States.
