Immunity Escape, Highly Contagious: XBB.1.5 Is Dominant Sub-Variant In US

Several European countries have sounded alert over the new Omicron subvariant that has caused a spike in Covid-19 cases in the US since the last month. On Friday, US Centers for Disease Control and Prevention said over 27% of Covid-19 cases in the United States were now caused by Omicron XBB.1.5, a highly contagious subvariant. In the last week of December 2022, the subvariant constituted over 40% of the Covid-19 cases in the US.

Expressing concern over the new variant, Germany's health minister Karl Lauterbach said that Berlin was closely monitoring the situation. "Hopefully we get through the winter before such a variant can spread among us," he wrote on Twitter on Wednesday.

While there has been a gradual slump in Covid-19 cases globally, new variants emerging in countries like China and US have prompted renewed concerns over the pandemic. Countries such as China, US, South Korea and Brazil witnessed a spike in December 2022. Omicron sub-variant BF.7 was reported to be dominant in these countries.

"Ironically, probably the worst variant that the world is facing right now is actually XBB," Dr Michael Osterholm, an infectious disease expert at the University of Minnesota, was quoted as saying by Reuters.

Here is all you need to know about the new Omicron sub-variant XBB.1.5

Where has Omicron sub-variant XBB.1.5 been detected?

The subvariant is also being called "Kraken" and is likely to have originated in the US between November and December 2022, EuroNews reported. A dominant strain in the US, Omicron sub-variant XBB.1.5 has reportedly been found in 28 other countries.

The first case of the XBB.1.5 sub-variant in South Africa was detected on Saturday, Bloomberg reported.

"There is intense transmission and pressure on health systems particularly in temperate regions of the northern hemisphere, and a recombinant sub-variant spreading quickly. XBB.1.5 is the recombinant of two BA.2 sub-lineages," WHO said on January 4.

Maria Van Kerkhove, the Covid-19 technical lead of the WHO said that XBB.1.5 is the most transmissible variant that has been detected yet.

How dangerous is XBB.1.5?

While the WHO does not have any data on the severity of the disease caused by the new sub-variant, the data shows the high transmissibility of the virus.

"We do expect further waves of infection around the world, but that doesn't have to translate into further waves of death because our countermeasures continue to work," Kerkhove was quoted as saying by Reuters.

The report also quoted Professor Andrew Pollard of the Oxford Vaccine Group saying that XBB.1.5 is not of more concern than earlier variants of the virus.

According to Bloomberg, the new variant has got scientists worried because it has shown signs of escaping natural immunity as well as that provided by vaccines or previous infections.