As the world continues to grapple with the ever-evolving COVID-19 pandemic, a new variant named Nimbus (NB.1.8.1) has emerged as a significant player in the ongoing viral landscape. Over the past few months, this strain has rapidly become the second-most common variant in the United States and is causing a stir globally due to its unique symptom profile and swift spread.
According to the U.S. Centers for Disease Control and Prevention (CDC), in the two-week period ending June 7, 2025, approximately 37% of new COVID-19 cases in the country were attributed to the Nimbus variant. This marks a dramatic increase from just 15% in the previous two-week reporting period, and an even more striking jump from 5% a month earlier. The variant’s rapid ascendance suggests it is outcompeting previous strains, including the well-known Omicron variant.
Experts believe Nimbus is more contagious than its predecessors, a factor that has triggered concerns about a potential summer wave of infections in the United States and other parts of the world. The variant has already been identified as the cause of COVID-19 resurgences in China and several Asian countries, with European experts also predicting a possible rise in cases there. The World Health Organization (WHO) has classified Nimbus as a “variant under monitoring,” noting that while it is spreading quickly, there is no evidence so far that it causes more severe illness or higher mortality than previous strains.
One of the most talked-about features of the Nimbus variant is an unusually severe sore throat symptom, which has been described by patients as feeling like “swallowing razor blades.” This vivid description, often referred to as “razor throat,” has captured public attention and is emerging as a hallmark symptom of the new strain. Medical professionals liken the intense throat pain to a severe case of strep throat, making it particularly uncomfortable but not life-threatening.
Beyond the razor blade sore throat, Nimbus shares many symptoms with earlier COVID-19 variants. These include fever, aches, chills, congestion, cough, shortness of breath, fatigue, loss of taste or smell, headache, nausea, vomiting, and diarrhea. Dr. Leana Wen, an emergency physician and clinical associate professor at George Washington University, explains that the symptoms can range widely, from allergy-like signs such as a stuffy or runny nose to more flu-like manifestations including fever, sore throat, and body aches.
Despite the discomfort caused by these symptoms, health officials urge the public not to panic. The variant is less lethal than the original strains that dominated the pandemic’s early years, and many patients are managing their illness through home isolation. For example, as of June 3, 2025, Oneida County in New York reported a “low” community risk level with just 1.7 weekly COVID admissions per 100,000 people.
Dr. Kent Hall, former Chief Physician Executive at MVHS, offers insight into the virus’s evolution: “The virus has evolved... And this is what viruses do. Their whole reason to live is to propagate. If they were so bad that they killed everybody right away, then actually that would be detrimental to their lifespan.” He predicts that COVID-19 will not disappear but will instead become a seasonal illness similar to the flu or common cold, with society learning to live alongside it.
Regarding vaccine efficacy, there remains some uncertainty. WHO surveillance data suggest that Nimbus may have some degree of immune escape, meaning it could partially evade immunity from previous infections or vaccinations. However, because it is a close descendant of strains against which vaccines have proven effective, current vaccines are still expected to offer some protection. Federal health authorities are actively working on the formulation of the fall 2025 COVID-19 vaccine update, likely aiming to ensure coverage against Nimbus.
Dr. Wen advises that individuals at higher risk—such as those aged 65 and over or people with chronic medical conditions—should consider getting another vaccine dose now if eligible. This precaution could offer additional protection should a summer wave materialize. Younger, generally healthy individuals who have not yet received the 2024-25 vaccine formulation might also consider vaccination before eligibility guidelines potentially change.
Precautionary measures remain consistent with previous COVID-19 guidance. Vulnerable populations are encouraged to avoid crowded indoor settings when possible and to wear well-fitting N95 or equivalent masks in high-risk environments, such as busy train stations or healthcare facilities. Those planning to visit vulnerable individuals should minimize exposure to high-risk settings in the days leading up to the visit to reduce the chance of transmitting not only COVID-19 but other respiratory illnesses as well.
Internationally, the Nimbus variant has been detected through airport screenings of travelers arriving from Asia in U.S. states including California, Virginia, New York, and Washington. In India, the Indian SARS-CoV-2 Genomics Consortium (INSACOG) has identified Nimbus among four circulating variants, alongside LF.7, XFG, and JN.1.16. Despite the presence of these variants, India’s active COVID-19 caseload stood at a relatively low 5,608 cases as of June 20, 2025, suggesting a downward trend in infections.
While the public remains watchful, health officials emphasize the importance of vigilance without alarm. Sir Richard Dearlove, commenting on the pandemic’s progression, highlighted the need for awareness: health officials continue to urge the public to remain alert for signs of the virus, recognizing that COVID-19 remains a persistent challenge.
In sum, the Nimbus variant embodies the virus’s ongoing evolution—more contagious yet less deadly, with distinctive symptoms that have captured attention worldwide. As the global community navigates this phase, the focus remains on monitoring, vaccination, and sensible precautions to manage the virus’s impact while adapting to its new normal.
