- The Delta variant is "more infectious" than the Alpha variant
- The Delta variant is present in all states
- Role of the variant in breakthrough infections has been found to be big
The coronavirus variant first found in India, the Delta strain, is highly infectious and fast-spreading and drove the savage second surge of COVID-19 in the country, a government study has found.
The Delta variant - or the B.1.617.2 strain - is "more infectious" than the Alpha variant first detected in Kent, UK, says the study by scientists of the Indian SARS COV2 Genomic Consortia and the National Centre for Disease Control. The study was launched to investigate what caused the second surge.
The Delta variant is, in fact, 50 per cent more contagious than the Alpha strain, the study says.
But the scientists say there is no evidence yet of the role of the Delta variant in causing more deaths or in the greater severity of cases.
Significantly, the UK's Public Health England (PHE), which monitors Covid variants in the country, says early evidence suggests there may be an "increased risk of hospitalisation with the Delta variant compared to the Alpha but adds that more data is needed. "With this variant now dominant across the UK, it remains vital that we all continue to exercise as much caution as possible," Jenny Harries, Chief Executive, UK Health Security Agency, was quoted as saying by Press Trust of India.
The India study, which is still ongoing, says there are more than 12,200 "Variants of Concern" in the country, as revealed by genomic sequencing, but their presence is miniscule compared to the Delta variant, which replaced all other variants in the second wave.
The study says the Delta variant is present in all states but has infected most in Delhi, Andhra Pradesh, Gujarat, Maharashtra, Odisha and Telangana, which were the worst hit in the second surge.
The role of the Delta variant in breakthrough infections - or Covid infections after vaccination - has also been found to be big. There are no such cases when it comes to the Alpha variant, the study finds.
Genome sequencing of 29,000 Covid case samples have been done in India, the study says. The B.1.617 has been found in 8,900 samples. More than 1,000 of those samples tested for the Delta variant.
India has recorded over 2.85 crore Covid cases so far, with 1.32 lakh new cases, according to government data. But experts believe the second wave is on the wane; the positivity rate has been below 10 per cent for 11 days running.