New Covid-19 variants are drawing global attention as cases rise in the UK and the US. The Stratus variant, also known as XFG, carries mutations that help it evade immunity. UK hospital data shows Covid positivity among patients with respiratory symptoms climbed from 5.8% on July 26 to 7.6% on August 10. That marks a 31% increase in just two weeks, according to the UK Health Security Agency.
Experts warn the surge could mark the start of a new wave.
“The rise in Covid positivity is a concern,” said virologist Professor Lawrence Young.
He added that the trend demonstrates the spread and persistence of new Covid-19 variants.
What We Know About the Variants
Stratus is a recombinant variant that combines earlier strains. Scientists have not linked it to more severe illness, but it is spreading quickly. Another variant, NB.1.8.1, also called Nimbus, first appeared in Asia in January 2025. It has spread to 22 countries and now makes up more than 10% of global Covid sequences submitted to GISAID.
The World Health Organization (WHO) designated Nimbus a Variant Under Monitoring and rated the public health risk as low. Current vaccines still protect against severe illness caused by these new Covid-19 variants.
Situation in South Africa
South Africa has not detected Nimbus or widespread Stratus cases. Surveillance data shows Covid infections remain low. High immunity levels from past infections and vaccines give South Africans added protection against severe illness.
Health officials urge the public to stay cautious: wash hands regularly, cover coughs, wear masks around vulnerable people, and keep distance when unwell. The Network for Genomic Surveillance in South Africa continues to track new Covid-19 variants.
The rise in cases abroad raises concern, but local experts insist South Africa faces no immediate threat. Strong immunity levels and ongoing monitoring leave the country better prepared. Even so, health officials stress the importance of vigilance.
