New Delhi (SunstarTV Bureau): The Delta variant or B.1.617.2 strain, which was first detected in India, is more infectious than the Alpha variant or B.1.1.7, first detected in the United Kingdom, and is also the reason behind the second wave of the Covid-19 pandemic, reveals a study conducted by a team of scientists from different Indian institutions.
“Our data indicates B.1.617.2 shows high transmissibility and surges without any increase in case fatality rate (CFR). We estimate the transmissibility to be as much as 50% greater than B.1.1.7. Viral load of B.1.617.2 appears to be higher than B.1.1.7,” said their study in its conclusion. The scientists noted B.1.617.2 is capable of creating “very fast-rising outbreaks”, importantly with “vaccination breakthroughs” (infections after vaccination). “We would re-emphasise that prior infections, high seropositivity and partial vaccination are insufficient impediments to its spread, as seen in Delhi, and strong public health response will be needed globally for its containment,” the study said.
The study was conducted by scientists from National Centre for Disease Control, Institute of Genomics and Integrative Biology (CSIR-IGIB), Indian SARS-CoV-2 Genomic Consortia (INSACOG) and others.
For the study, samples from 10,427 adults were obtained of which 1,399 samples were from Delhi-based laboratories and offices in Phase 1 and 9,918 samples were obtained of which 1115 samples were from Delhi in Phase 2.
On the origin of SARS-CoV-2 outbreaks in north India this year, the study noted that the outbreak in April in Delhi was preceded by outbreaks in Kerala, Maharashtra and Punjab.
“While no Variants of Concern (VOC) was identified in Kerala in January 2021, the outbreak in Maharashtra has been related to B.1.617.1 and in Punjab to the introduction of B.1.1.7,” it said.
So, the B.1.617 lineage of CoV-2 had been first reported from Maharashtra and later seen in other states such as Delhi, Gujarat, Telangana, Andhra Pradesh and West Bengal.
The scientists said the surge of SARS-CoV2 infections in Delhi was best explained by the introduction of a new highly transmissible VOC, B.1.617.2, with likely immune-evasion properties; insufficient neutralising immunity despite high seropositivity; and social behaviour that promoted transmission.
(Sources: Times of India)
