BENGALUR: Surveillance has been intensified in Karnataka after WHO’s recent report outlining findings of a potentially new variant of concern -- the XE variant, a hybrid of two Omicron strains, BA.1 and BA.2. Sewage surveillance and genome sequencing have so far not found any traces of new variants, and the dominant variant in Karnataka has been the BA.2 lineage of Omicron.
The XE variant was first detected in the UK and is estimated to spread 10 per cent more easily than BA.2, which itself was more transmissible than the original Omicron variant. In this background, and also China’s finding of two novel Omicron sub-variants that have no similarity to the existing sequences, the state government has been strictly monitoring international travellers from UK and other countries showing an increase in Covid-19 cases.
Samples are being collected randomly from international travellers, and those who are symptomatic are being tested too. If they test positive, those samples are compulsorily being genome-sequenced, explained D Randeep, Commissioner, Department of Health and Family Welfare. However, he confirmed that so far, no one has tested positive for the XE variant and reports of three positive samples from the UK are awaited. “From January 2022, 71 Covid-positive travellers from UK have arrived in Karnataka. Of these cases, 57 came in January, 11 in Febraury, 3 in March and none till April 2. All of them have shown BA.2 variant of Omicron but not the XE variant,” Randeep said.
However, he explained that sewage surveillance would help pick up if there are any asymptomatic patients who have caught this strain of variant, and hence, monitoring for this has been upped in the state. Meanwhile, INSACOG is also watching out for this variant, and monitoring genome samples from various states.
Dr Shahid Jameel, senior virologist and fellow at Green Templeton College, University of Oxford, UK, told TNIE, “I am not sure if any XE variant been detected in India. There are about 800 cases so far in the UK. But considering it’s a mixture of BA.1 and BA.2, and almost all Indians have antibodies to SARS-CoV-2 by way of prior infection and/or vaccination, I doubt it would make any difference to India,” he said. As the XE variant is a recombinant variant, Dr Jameel, who is also visiting professor at Ashoka University, said that recombinant variants are not unusual. “The key is whether it has any growth advantage over its parent strains. There isn’t clear evidence on that, according to the latest UK HSA report,” he explained.
WAVES AND VARIANTS