The virus that causes COVID-19, SARS-CoV-2, naturally changes its genetic makeup over time, leading to the emergence of new strains or variants. These mutations often allow the virus to spread more easily or evade the body’s immune defenses. Because of this continuous evolution, the symptoms and overall characteristics of the illness can shift from one wave to the next. Public health officials constantly monitor these genetic changes to understand their potential impact.
Identifying the Current Dominant Variant
The strain currently driving the majority of cases in early 2026 is the XFG variant, unofficially designated “Stratus.” This variant is a descendant of the Omicron lineage and rapidly achieved dominance due to its increased ability to bypass immunity from previous infections or vaccination. XFG possesses specific mutations on its spike protein that enhance its ability to bind to human cells and evade antibodies. While highly transmissible, its emergence has not been linked to an increase in the overall severity of illness compared to other recent Omicron sub-lineages. This strain continues the trend of viral evolution toward greater contagiousness without a proportional increase in the risk of severe disease.
The Specific Symptom Profile
The XFG variant’s symptom profile is characterized by upper respiratory issues, making it difficult to distinguish from a common cold or the flu without testing. The most frequently reported symptoms include an intense sore throat and significant nasal congestion or a runny nose. These localized symptoms are often the first signs of illness, appearing two to four days following exposure.
Systemic symptoms are also common, with many people experiencing fatigue, a headache, and muscle or body aches. A mild fever or chills may be present, but high, sustained fevers are less common than in earlier pandemic waves. A persistent dry cough is a frequent complaint, sometimes accompanied by a feeling of chest tightness that is typically inflammatory rather than a sign of pneumonia.
Gastrointestinal issues, such as nausea, vomiting, or diarrhea, are reported in some cases, although they are less frequent than the respiratory and systemic symptoms. Importantly, the once-prominent symptom of a persistent loss of taste or smell is now reported much less often with the XFG variant. The majority of symptoms tend to be mild to moderate, typically resolving within five to ten days for most healthy individuals.
How Symptoms Have Evolved Over Time
The current symptom profile represents a significant shift from the disease caused by earlier variants like the initial SARS-CoV-2 strain or the Delta variant. Earlier strains were frequently associated with lower respiratory tract infections, leading to a high incidence of severe pneumonia and acute respiratory distress. The XFG variant, like its recent Omicron predecessors, primarily targets the upper respiratory system, resulting in less severe lung involvement.
The prominence of symptoms like loss of taste and smell has decreased dramatically with the newer variants. This change reflects the virus’s adaptation to the human host and the broad population immunity established through vaccination and prior infection. The illness duration has also generally shortened, with many people experiencing a rapid onset and quicker resolution of symptoms compared to the weeks-long illness seen with the original strains.
Actions to Take When Symptoms Appear
If you develop cold or flu-like symptoms, testing remains the most reliable way to confirm a COVID-19 infection, especially since symptoms overlap with other respiratory viruses. At-home rapid antigen tests should be used immediately upon symptom onset. If the initial test is negative but symptoms persist, repeat the test 24 to 48 hours later, as the viral load may not have been high enough for initial detection.
Current public health guidance recommends staying home until you have been fever-free for a full 24 hours without medication and your other symptoms are improving. Once resuming normal activities, wearing a high-quality mask and limiting close contact for an additional five days helps reduce transmission. Home care focuses on symptom relief, including rest, hydration, and using over-the-counter medications for fever, aches, and nasal symptoms. Individuals at high risk for severe illness, such as those over 65 or with certain medical conditions, should contact a healthcare provider immediately upon testing positive for potential antiviral treatments.