In brief

• The XFG variant, the most frequently detected in the world at the end of August 2026, produces symptoms similar to a cold, flu and allergies.
• Doctors recommend an antigen test for fever, cough or sore throat, especially when sick people are around.
• It is worth contacting a doctor earlier in case of severe or long-lasting symptoms and in elderly people.

Symptoms that are hard to tell apart

The XFG variant, also called Stratus, emerged in 2025 and is still circulating among people. According to the World Health Organization, at the end of August 2026 it was the most frequently detected COVID-19 variant in the world (Takie są teraz objawy COVID-19. Łatwo o pomyłkę w diagnozie – Medonet). The American Food and Drug Administration selected it as the target strain for new vaccines for the 2026-2027 season.

The course of the disease can be similar to a cold, flu or allergies, which makes diagnosis based on symptoms alone difficult. For this reason, during the infection season, experts advise taking a test rather than guessing.

What to do with worrying symptoms

If fever, cough, sore throat or weakness appear and sick people are around, it is worth taking an antigen test. In crowded and enclosed spaces, a mask still limits contact with the viruses circulating this season.

It is worth contacting a doctor earlier if symptoms are severe, last longer, or occur in elderly people or those with coexisting illnesses.