A new Covid variant ‘XBB’ discovered last year has quickly become the dominant strain in the United States, earning it a disturbing title in the process. Some have dubbed it the “Kraken variation,” and it has already been found in at least 28 other nations, according to the World Health Organization. Is it more hazardous? Is it more easily spread? And how will it affect the Covid outbreak in China?
Kraken’ or ‘XBB: What exactly is the new variant?
XBB.1.5 is a descendent of the omicron XBB subvariant, which is a hybrid of two previous strains: BA.2.75 and BA.2.10.1. Since the WHO first expressed concerns about the original XBB version last October, it has already triggered waves of illness in countries such as Singapore and India.
How quickly is XBB.1.5 spreading?
While it accounted for only 1% of all Covid cases at the start of December, figures from the US Centers for Disease Control and Prevention reveal that by the end of the month, it had risen to become the dominant strain, accounting for approximately 41% of all infections. This figure has risen above 70% in the northeastern states. XBB.1.5 is “the most transmissible sub-variant which has been detected yet,” said WHO’s Covid-19 technical lead, Maria Van Kerkhove, during a press conference on Jan 4.
The sub-variant has a significantly stronger affinity for ACE2, a critical receptor for the virus, which allows it to connect more easily and increases its transmissibility, according to scientists.
Is it riskier than prior variants?
There have been no reports of significant changes in severity between instances produced by XBB.1.5 and prior versions. XBB.1.5, like other strains that have alarmed experts, is gaining attention because of symptoms of immunity escape. That is, it can elude natural immunity or past vaccine protection and re-infect persons who have recovered from a previous bout of Covid.
Data on the severity of XBB.1.5 and its proclivity to cause severe disease or death remain scarce. Previous Covid medicines, such as monoclonal antibody therapy, were made ineffective by previous strains. This pattern is expected to continue with the next variant. Scientists warned that subvariants like XBB pose “serious threats” to current Covid vaccinations in a recent peer-reviewed article published in the journal Cell. Higher transmissibility also means that more people are likely to become infected and suffer severe consequences.
It’s unknown whether the US experience with XBB.1.5 will be replicated in other nations. America, unlike many other wealthy countries, has poor vaccination rates. Only 15% of people aged five and up have had an updated bivalent booster dosage. The percentage is slightly higher among the fragile elderly, including those aged 65 and older, with less than four in ten receiving the shot. Covid hospitalization rates are already on the rise, as are other winter-season diseases such as influenza.
The WHO intends to produce an updated risk assessment for the variation in the coming days.
Is it still in China, and what effect will it have?
China, which is experiencing a surge in infections following the repeal of its strict Covid Zero policy in recent weeks, has yet to report any domestic cases of XBB.1.5. Shanghai has identified three infections caused by the variation, all of which were imported. However, health organizations around the world, notably the World Health Organization, have expressed concern that China is not giving enough genome sequencing data to draw definitive conclusions.
Meanwhile, two other omicron strains, BA.5.2 and BF.7 are driving the country’s Covid surge. According to statistics from the Chinese Center for Disease Control and Prevention’s genomic sequencing, they account for 97.5% of all local infections.
While officials have attempted to calm public fears that the XBB strains could cause new waves of infection, the public, already concerned about the stressed healthcare system and limited treatment options, is skeptical. An anti-diarrheal drug sold out across China as frantic shoppers scooped it up in response to a widely circulated viral post saying the XBB form may cause vomiting and diarrhea.
Where did the name ‘Kraken’ come from?
An expert group created by the WHO is currently naming Covid variants. Using the Greek alphabet, it detects so-called variations of concern that have potential global public health relevance, such as lowering the efficiency of current pandemic efforts. The convention applied to previous strains such as alpha, beta, and delta.
However, the most recent Greek-named variety, omicron, appeared more than a year ago, leaving no possibility for the formation of new, considerably different strains. Omicron has given birth to other lineages, notably XBB 1.5, and their names are derived from a combination of alphabets and numbers known as “Pango.”