As flu season takes hold, the United States is seeing a sharp rise in COVID-19 cases driven by a new strain known as the Stratus or XFG variant. Health officials warn that both viruses are circulating widely, and vaccination remains the strongest defense against serious illness.
According to data from the Centers for Disease Control and Prevention (CDC), as of September 20, Nevada and Utah had reported very high levels of COVID-19 detected in wastewater samples, signaling a nationwide uptick in infections. The Stratus strain has been spreading rapidly since early September and shares many similarities with previous variants, though it comes with one distinct symptom.
Recognizing COVID-19 Stratus Symptoms
The new strain’s most notable sign is what doctors call a “razor blade throat,” a term used to describe an unusually severe sore throat that feels sharp and painful. Dr. Aaron Glatt, chair of medicine and chief of infectious diseases at Mount Sinai South Nassau in New York, told TODAY that this symptom has become a key indicator of Stratus infections.
Other common symptoms, according to the CDC, include fever or chills, coughing, shortness of breath, congestion, fatigue, headache, body aches, nausea, and loss of taste or smell.
How to Tell the Difference Between COVID-19 and the Flu
Because flu and COVID-19 share several overlapping symptoms, distinguishing between them can be difficult without testing. The flu typically comes on suddenly and may cause fever, sore throat, coughing, runny or stuffy nose, fatigue, muscle aches, and headaches. Vomiting and diarrhea can occur, though these are more common in children than adults.
Vaccines Remain the Best Defense
Health experts continue to emphasize vaccination as the most effective way to prevent severe illness and hospitalization. The CDC recommends that everyone six months and older receive a flu shot for the 2025–2026 season. While the vaccine may not always prevent infection, it significantly reduces the severity of symptoms and the likelihood of complications.
Caitlin Rivers, an infectious-disease epidemiologist at the Johns Hopkins Center for Health Security, told The Washington Post she plans to get her flu shot by the end of October. She also noted the importance of vaccinating children, who are often exposed to viruses at school.
The COVID-19 vaccine remains widely available, though some people report mild side effects like arm soreness. Health officials advise waiting a few days between receiving the flu shot and the COVID-19 vaccine if side effects are a concern.
As the colder months approach, experts urge Americans to stay vigilant, get vaccinated, and practice good hygiene to help limit the spread of both viruses.