A new Covid strain called XFG, or “Stratus,” is spreading across the United States. First detected in March, it has quickly become the driver of rising infection rates. According to the CDC, national wastewater data shows viral activity moved from moderate to high in just one week.

Researchers say XFG is more contagious than earlier strains. Mutations in its spike protein allow it to partially evade antibodies from vaccines or prior infections. While this makes it easier to spread, current evidence shows it is not more deadly than previous versions.

Even so, faster transmission raises risks for older adults, those with health conditions, and the unvaccinated. Hospitals are being asked to prepare for a potential surge in patients as infections climb. The CDC stresses that updated vaccines, good ventilation, and mask use in crowded places remain effective tools for protection.

The rise of XFG is a reminder that Covid is still evolving. While the variant may not cause more severe illness, its speed of spread keeps pressure on communities and healthcare systems. Staying alert—and continuing simple preventive steps—remains the best defense.