Fourth wave scare! XE variant of Covid-19 in India? All we know about new variant and its symptoms

The XE variant is a recombinant of BA.1 and BA.2, the sub-lineages of SARS-CoV-2, the virus which causes Covid-19. In addition to those, it has three other mutations which were not there in Omicron or BA.1 or BA.2. XE is 10 per cent more infectious than Omicron, says experts.

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Mumbai: Yesterday (April 6), it was reported that Maharashtra has detected the first case of the XE variant of SARS-CoV2 in India. The patient is reportedly a 50-year-old female South African national who had come to India on February 10. She was found to be Covid-19 positive after she was tested on February 27. Her lab sample was referred to Mumbai's Kasturba Hospital Central laboratory for genome sequencing. "It has been found to be a new XE variant in initial sequencing. Though GISAID also confirmed it, INSACOG has decided to go for another round of genomic sequencing at the national laboratory for confirmation of the XE variant," the health department said.
The patient is asymptomatic and was found to be RT-PCR negative on repeat testing.

Here's what we know about the XE variant and its symptoms so far:

XE variant: A recombinant of BA.1 and BA.2

The XE variant is a recombinant of BA.1 and BA.2, the sub-lineages of SARS-CoV-2, the virus which causes Covid-19. In addition to those, it has three other mutations which were not there in Omicron or BA.1 or BA.2. "That is why it is called XE. It will now be a variant," Rakesh Mishra, Director of the Tata Institute of Genetics and Society, Bengaluru, told PTI.

'XE can be the most contagious Covid variant so far'

Some experts say that it could be the most contagious Covid variant yet. Commenting on its severity and transmissibility, Rakesh Mishra said based on infectivity data collected in the UK, XE is 10 per cent more infectious. 

Symptoms of XE: How worried should we be?

"There is no information whether the clinical symptoms are worse, or whether its immune escape is more. Data is not available for the same," Mishra noted.  The World Health Organization (WHO) has reportedly mentioned that the XE mutation is currently being tracked as part of the Omicron variant. Symptoms of Omicron include fever, sore throat, scratchy throat, cough and cold, skin irritation and discoloration, and gastrointestinal distress.

Senior epidemiologist Dr Raman Gangakhedekar, former head scientist of the Epidemiology and Communicable Diseases Division at the Indian Council of Medical Research (ICMR), said when a recombinant occurs, it tends to last for a lesser time. "Recombinant events are chance events because two different types of viruses are in the body and they tend to develop a recombinant new virus," Gangakhedekar said. He said the virus fitness does not increase by a recombinant event. It is unlikely to be stable as recombinants are rare events. 

Is XE a variant of concern?

Anurag Agrawal, Dean, Biosciences and Health Research at Ashoka University, said there is "no critical global signal of concern as of now" with regards to XE. The World Health Organisation on April 2 said XE appears to be more transmissible than previous strains of the coronavirus and stressed that Covid-19 remains a public health emergency of international concern, and warned that it is too early to reduce the quality of surveillance. 

First detected in the UK

The WHO said in its latest update that the XE recombinant (BA.1-BA.2) was first detected in the UK on January 19 and more than 600 sequences have been reported and confirmed since then. The XE variant has also been detected in Thailand and New Zealand.

Meanwhile, hours after the report of detection of  XE variant of Coronavirus in Mumbai, the Ministry of Health and Family Welfare has said present evidence does not suggest the presence of the new variant. FastQ files in respect of the sample, which is being said to be XE variant were analysed in detail by genomic experts of INSACOG who have inferred that the genomic constitution of this variant does not correlate with the genomic picture of 'XE' variant, Ministry of Health informed, reported PIB India.