New XBB.1.5 COVID variant 'most transmissible' yet detected, senior WHO official warns
The new XBB.1.5 variant of COVID is the "most transmissible" yet detected, a senior World Health Organization (WHO) official has warned.
The variant, which is a sub-variant of Omicron, is confirmed to be spreading in 25 countries, including the UK and US.
Dr Maria Van Kerkhove, the WHO's COVID-19 technical lead, told a press conference on Wednesday: "It is the most transmissible sub variant that has been detected yet.
"The reason for this are the mutations that are within... this sub variant of Omicron, allowing this virus to adhere to the cell and replicate easily.
