New COVID Variant Symptoms Seen in US Amid Surge in Summer Wave: Symptoms and States at Highest Risk
As the United States navigates the summer of 2025, a new wave of COVID-19 cases is sweeping across the country, driven by the highly transmissible NB.1.8.1 variant, nicknamed "Nimbus." This Omicron subvariant, which first emerged in China in January 2025, has become the dominant strain in the U.S., accounting for an estimated 43% of cases as of July 2025. With cases rising in at least 26 states and Washington, D.C., health experts are urging vigilance, particularly in high-risk areas. This blog explores the symptoms of the Nimbus variant, the states most affected, and key prevention strategies to stay safe during this summer surge.
Symptoms of the Nimbus Variant
The NB.1.8.1 (Nimbus) variant presents symptoms similar to those of previous Omicron strains, but one distinctive feature has caught the attention of both medical professionals and the public: a severe sore throat often described as "razor blade throat." This painful condition has become a hallmark of the variant, setting it apart from earlier strains. According to health experts, the symptoms of Nimbus include:
- Severe sore throat ("razor blade throat"): A sharp, painful throat condition that feels unusually intense.
- Mild cough: A persistent but generally mild cough.
- Fever: Elevated body temperature, often mild but occasionally more pronounced.
- Muscle aches: Generalized body aches or fatigue.
- Nasal congestion: Stuffy or runny nose, often mistaken for allergies or a common cold.
- Fatigue: Unusual tiredness or weakness.
- Headache: Mild to moderate headaches, sometimes accompanied by sinus pressure.
These symptoms are broadly consistent with earlier COVID-19 variants, but the "razor blade throat" stands out as a unique and particularly uncomfortable feature. Importantly, the World Health Organization (WHO) and experts like Dr. Jon LaPook from CBS News have noted that Nimbus does not appear to cause more severe illness compared to previous variants, with most cases remaining mild, especially among vaccinated individuals. However, the variant’s high transmissibility means it spreads rapidly, particularly in crowded indoor settings during the summer months when people seek air-conditioned spaces to escape the heat.
States at Highest Risk
As of July 22, 2025, the Centers for Disease Control and Prevention (CDC) reports that COVID-19 cases are either growing or likely growing in 26 states and Washington, D.C., with no states showing a decline in infections. The West and South are experiencing the most significant increases in transmission, with states like Virginia, North Carolina, Texas, Illinois, Kentucky, and Ohio among the hardest hit. Wastewater surveillance data from WastewaterSCAN indicates that national COVID levels are currently in the "medium" category, with a 54% increase in viral RNA detected in wastewater between June 30 and July 12, 2025.
Specific hotspots include:
- Virginia: Seeing a notable uptick in cases, particularly among young children and high-risk groups.
- Texas: Reporting increased emergency room visits for COVID-19, with the Nimbus variant driving the surge.
- North Carolina: Experiencing a steady rise in infections, fueled by declining mask usage and summer gatherings.
- California: Early detection of Nimbus through airport screening programs has contributed to its spread in the state.
- New York: Urban areas, particularly New York City, are seeing increased cases linked to travel and social gatherings.
The CDC’s data also highlights a significant rise in COVID-related emergency room visits among young children under four years old, underscoring the need for heightened precautions in households with vulnerable populations.
Why Is This Summer Wave Happening?
Several factors are contributing to the 2025 summer surge:
- High Transmissibility of Nimbus: The NB.1.8.1 variant is described as a “slightly upgraded” version of its predecessor, LP.8.1, with mutations that enhance its ability to evade immunity from prior infections or vaccinations. By mid-June, Nimbus accounted for 37% of U.S. cases, up from 0% in April.
- Waning Immunity: As immunity from previous vaccinations or infections fades, many Americans are more susceptible to infection, particularly those who have not received the 2024-2025 COVID vaccine.
- Summer Behavior: Increased travel, large gatherings, and time spent in indoor, air-conditioned spaces during the hot summer months facilitate viral spread.
- Policy Changes: Recent decisions by the Trump administration and the FDA to limit access to updated COVID-19 vaccines for healthy adults under 65 and pregnant women have raised concerns about reduced protection for some groups, potentially exacerbating the spread.
While the current test positivity rate of 5.1% (as of July 14, 2025) is significantly lower than the 18% peak of last summer’s wave, experts warn that poor data quality may be masking the true extent of the surge. Dr. Michael Hoerger from Tulane University School of Medicine noted, “The situation could be a lot worse than what people are seeing,” emphasizing the need for better surveillance and testing.
Prevention and Treatment: What You Can Do
To protect yourself and others during this summer wave, health experts recommend the following:
- Vaccination: The 2024-2025 COVID-19 vaccines, targeting JN.1 and KP.2 lineages, remain effective against Nimbus and are recommended for most adults, particularly those over 65, immunocompromised individuals, or those with underlying conditions. However, new FDA guidelines limit access for healthy adults under 65, so consult your healthcare provider to determine eligibility.
- Testing: If you experience symptoms like a sore throat or fever, test for COVID-19 immediately. At-home tests are reliable but may not detect early infections, so retest after 48 hours if the initial result is negative. Free testing is available at over 19,000 locations nationwide through the CDC’s ICATT program.
- Antiviral Treatment: For high-risk individuals who test positive, antiviral medications like Paxlovid can reduce the risk of severe illness by up to 86% if started within five to seven days of symptom onset.
- Masking: Wearing a mask in crowded indoor settings, such as public transportation or movie theaters, is advised, especially for high-risk groups. Dr. Leana Wen from CNN emphasizes that masks are highly effective at preventing transmission of respiratory viruses.
- Hygiene and Ventilation: Regular handwashing, using hand sanitizer, and improving indoor ventilation can reduce the risk of infection.
- Isolation: If you test positive or experience symptoms, isolate from others, including household members, to prevent spreading the virus.
Looking Ahead
While the Nimbus variant is highly contagious, experts like Dr. William Schaffner from Vanderbilt University and Dr. Andrew Pekosz from Johns Hopkins suggest that this summer wave is unlikely to match the severity of previous years, thanks to high population immunity (up to 96.4% antibody positivity as of fall 2022) and milder disease profiles of Omicron subvariants. However, the risk of long COVID remains a concern, with each infection potentially increasing the likelihood of lingering symptoms.
As the U.S. awaits the release of the 2025-2026 vaccines targeting the LP.8.1 variant this fall, health officials urge high-risk groups to consider getting a pre-summer booster if they haven’t been vaccinated in the past six months. For those in high-risk states or with vulnerable family members, staying proactive with testing, masking, and vaccination is critical to navigating this summer wave safely.
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