There may be confusion over whether India has detected its first XE Covid case, but there’s no doubt about the existence of the new recombinant variant of the novel coronavirus. Mumbai might have reported the first case of the XE recombinant, but the INSA COG has denied its presence after genome sequencing.
First detected in the United Kingdom, the new Omicron strain is known to be more transmissible than any previous strain, as per the World Health Organization.
Scientists are still studying XE, determining how it is different from previous Omicron strains such as the dominant BA.2 sub-variant, or even the lethal Delta variant that caused large-scale deaths in India last year.
Why is XE being called a recombinant?
First detected in the UK on January 19, the XE variant is a recombinant. This means it is a combination of the BA.1 and the subtype BA.2. In its latest update, the WHO said the new strain is known as the XE recombinant (BA.1-BA.2). XE belongs to the Omicron variant until significant differences in transmission and disease characteristics, including severity, may be reported. A recombinant strain means that it is a mutant hybrid of the two previous versions of the Omicron variant, BA.1 and BA.2.
According to the UK Health Security Agency, the new Omicron strain is being called a stealth variant because of its ability to evade detection. Professor Susan Hopkins, the UK Health Security Agency (UK HSA)’s chief medical advisor, said such variants are known as recombinant and usually die off relatively quickly.
So far there is not enough evidence to draw conclusions about transmissibility, severity or vaccine effectiveness, Hopkins told The Sun. As of March 16, XE had a growth rate 9.8 per cent above that of the so-called stealth BA.2 Omicron variant already known to be highly transmissible, the UK HSA said.
The agency cautioned that as this estimate has not remained consistent as new data have been added, it cannot yet be interpreted as an estimate of growth advantage for the recombinant.Numbers were too small for the XE recombinant to be analzsed by region, the UK HSA said. According to the agency, while there are signs of community transmission of XE in England, it remains less than 1 per cent of the totally sequenced coronavirus cases.
The new strain of the Omicron variant appears to be more transmissible than any previous strains.
Early-day estimates indicate a community growth rate advantage of 10 per cent as compared to BA.2. This finding, however, requires further confirmation. The BA.2 has been deemed to be the most contagious of all the variants so far.
How is XE different from Omicron and Delta?
As of now, the Omicron variant (BA.1) is fuelling China’s biggest wave since Wuhan’s initial outbreak in 2020. Classified as a variant of concern (VoC) when it was first detected in South Africa and Botswana, it quickly outcompeted the devastating Delta variant due to its high transmissibility. Soon, its sub-variant BA.2 proved to spread faster causing a surge in coronavirus cases in countries such as the United Kingdom. The Omicron variant was also responsible for India’s third wave in January.
Scientists are still studying BA.1 as well as its subtype BA.2, which surpassed the original strain in March to become the predominant variant.
Delta (B.1.617.2), meanwhile, proved to be lethal leading to large-scale deaths and hospitalisations. It was first identified in India in late 2020 and soon spread throughout the world becoming a predominant version until Omicron took its place in mid-December.
What is the WHO’s verdict so far?
According to the WHO, the BA.2 sub-variant of Omicron is still the most dominant as 86 per cent of all sequenced cases are being attributed to it. The XE recombinant may not have been classified as a VOC, yet but its extremely high transmissibility could mean that it becomes the most dominant strain in the near future, according to the WHO. The variant only accounts for a small fraction of cases as of now.
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