What is XBB Covid? The new Omicron variant leading a surge in cases

New Covid strains are sparking fresh health concerns across the globe as the world welcomes 2023.

Descendants of the highly-transmissible Omicron variant - XBB and XBB.1.5 - have seen a surge in cases in many countries over winter.

But what exactly are they?

XBB is a subvariant of the Omicron BA.2 variant, and XBB.1.5 is a subvariant of XBB.

Japanese researchers have studied XBB’s characteristics, and results suggest that the subvariant is highly transmissible and has developed resistance to immunity.

Countries including the UK, US, China, India, Pakistan and Australia have all reported cases of XBB and XBB.1.5.

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