Over a 3rd of Covid samples in West Bengal have 'unassigned' strain

KOLKATA: A significant percentage of Covid samples collected from across Bengal for genome sequencing till June 27 does not match any of the known variants, according to data released by INSACOG (Indian SARS- Cov 2 Genomics Consortium), a joint initiative of the Union health ministry and the department of biotechnology with Council for Industrial & Scientific Research and Indian Council of Medical Research .
While Omicron variants were detected in 64% of the samples, 36% had an "unassigned" strain that could be an altogether new variant that has not yet been identified, said experts. "The unassigned samples will be sent to WHO for identification," said an official associated with the analysis. In Kolkata, 31.4% of the samples had this "unassigned" variant .
The samples were analysed by a leading city-based institution and collected from the National Institute of Biomedical Genomics Kalyani.
"The presence of a new or a rare strain should be taken seriously since we are approaching the peak of the current surge. It may indeed evade vaccines and push up the mortality rate. We are around 7-14 days away from the peak and must keep our fingers crossed. Vigilance and awareness are required to check transmission that will aid mutation and create new strains like this one," said Institute of Post-Graduate Medical Education & Research (IPGMER) professor Diptendra Sarkar.
In another recent genome analysis, the new BA.5 strain was traced in some samples in the state, according to the director of health services.
Unassigned strain: Need to take guard, say docs
Genome sequencing of 560 Covid positive samples from the state has identified 11 Omicron sublineages, of which 54% are BA.2 and 28% BA.2.38, INSACOG data has revealed. In Kolkata, 40% of the samples were classified as BA.2, the most common Omicron sublineage that is known to cause a mild disease, but a significantly high 31.4% had the “unassigned” strain.
In North and South 24 Parganas, the unassigned variant was found in 32.6% and 42% of the samples respectively. “This could be a mutated strain that remains mild like the BA.2. But we need to guard against it for two reasons. First, it could turn the existing vaccines ineffective because they are not designed to act against it. Secondly, even if it triggers a mild disease in a majority of the population, for the elderly and the comorbid, the strain could turn out to be more dangerous due to their low immunity and lead to hospitalisation and even death,” said CMRI Hospital pulmonology director Raja Dhar. As many as 281 samples belonged to those who were fully vaccinated.
While 36.7% of them were struck by Omicron BA.2 variant, 33.5% had the new strain. Among the 22 paediatric samples, 10 samples were from vaccinated patients and five had the unassigned variant. According to Dhar, the number of positives is fallacious in this wave because people are not testing. “The elderly and the infirm with comorbidities are becoming very unwell. This is a very small percentage. However a ‘very small percentage’ is a large absolute number in our populous country,” he said and urged people to maintain restraint for the next few days, avoid crowded places and wear masks. “These ‘mini peaks’ will continue every 3-4 months. It’s important to be cautious but get on with your life during these times,” Dhar added.