New COVID Variant ‘Stratus’ Takes Hold: Symptoms, Vaccine Efficacy And Global Risk Level

The variant, officially named XFG, is now the third most common in the US, but the WHO has rated its global health risk as “low” and confirms existing vaccines are effective against it.

August 9, 2025: A new strain of COVID-19 named XFG, or “Stratus,” is spreading in the US this summer. Health experts are keeping a close eye on how swiftly it expands. The CDC claimed that by the end of June, the variation was the third most frequent strain in the country, accounting for roughly 14% of all new cases.

XFG is a recombinant strain, which indicates that it has DNA from two other strains, F.7 and LP.8.1.2. The first time it was seen was in Southeast Asia in January. Scientists think it might have changes that help it avoid the immune system better, but there is no proof that it makes people sick or spreads faster.

The World Health Organization (WHO) has put XFG on its list of variants to watch, although it argues that it doesn’t pose a “low” risk to public health. The committee also said that the COVID-19 vaccines that are already out should still protect against the severe illness and symptoms caused by this strain.


The variation has been steadily growing, going from 0% of cases in March to 22.7% of cases worldwide by the end of June. The CDC adds that XFG symptoms are similar to those of early Omicron forms and include a fever, cough, fatigue, and a sore throat. Health professionals are encouraging individuals to be on the lookout and be checked out if they start to show signs.