Doctors reveal unusual symptoms of new Covid variants ‘Stratus’ and ‘Nimbus’ that are sweeping the US

Two newer COVID variants, NB.1.8.1 (“Nimbus”) and XFG/XFV-type descendants often called “Stratus,” have been monitored in the U.S. as part of the continuing evolution of Omicron-lineage strains. Health officials say these variants appear to spread efficiently, but current evidence does not show they are causing more severe disease than earlier recent variants.

Doctors say the symptoms are still mostly familiar, including fatigue, cough, congestion, headache, and fever. One symptom getting extra attention is an especially severe sore throat, sometimes described as feeling like “razor blades.” That description is not unique to these variants, but some recent patients have reported it more often.

The main concern remains older adults, people with chronic health conditions, and those with weakened immune systems. Public-health monitoring also continues to rely heavily on wastewater tracking, since it helps show where community spread is rising or falling.

Even when a case seems mild at first, doctors still warn people to take COVID seriously, especially if symptoms worsen or recovery feels unusually slow. The safest response is to rest, avoid spreading illness to others, and seek medical advice if symptoms become severe or do not improve.