Since May, a new variant of the Covid-19 virus, called Stratus, has been identified in the UK and continues to spread rapidly across the country, now accounting for 40% of all cases.
The Stratus variant responsible for Covid-19 has two scientifically named sub-variants, including XFG and XFG.3, both of which are spreading quickly.
Although not yet confirmed by experts, it is suspected that this new variant is more contagious than other Covid-19 variants due to mutations that alter its structure, potentially allowing it to evade the immune system.
Professor Lawrence Young, a virologist specializing in virus structure, stated that the rapid spread of the XFG and XFG.3 sub-variants is linked to changes in the virus’s ‘spike’ protein, which differs from other Covid-19-causing variants.
According to The Daily Mail, in May, cases caused by the Stratus variant made up only 10% of Covid-19 infections in the UK. However, the prevalence increased sharply, reaching 40% by June 2025.
Another factor contributing to the swift spread of this new variant is the waning immunity in the population, as many individuals have not been vaccinated for some time and thus have less protection against the virus.
Professor Young noted that the XFG and XFG.3 sub-variants could lead to a resurgence of Covid-19, but he also emphasized that current vaccines still offer some protection against the new Stratus variant.
The World Health Organization (WHO) has stated that, although the Stratus variant is not considered highly dangerous in terms of severity, it is spreading rapidly, now accounting for 22% of Covid-19 cases worldwide.
The Stratus variant was first identified in Canada earlier this year. By May, it had begun spreading to various countries, mainly in Europe, Africa, as well as in India and South America.
So far, no African country has reported cases of this variant. The symptoms of those infected with Stratus are similar to typical Covid-19 symptoms.
