- A study in India has found that the strain drove the second Covid surge
- No evidence of the role of Delta variant in more deaths, say scientists
- Delta variant has played a bigger role in infections after vaccination
Here are the top 10 updates on Delta variant:
The UK's Public Health England (PHE) says experts believe that Delta has now overtaken Alpha, the name given to the variant first detected in Kent, England. It also says variant cases are on the rise in several parts of the country.
The UK health body, which tracks variants, says early evidence suggests there may be an "increased risk of hospitalisation" with the Delta strain compared to the Alpha, although more data is needed to reinforce this view.
Official data says 278 people with the Delta variant went to hospital in an emergency this week. Last week, that number was 201. Most of these patients have not been vaccinated, according to PHE.
"With this variant now dominant across the UK, it remains vital that we all continue to exercise as much caution as possible," said Jenny Harries, Chief Executive, UK Health Security Agency.
Experts have urged people to "remain cautious" as the country approaches the next stage of the roadmap -- June 21 - when all lockdown restrictions are to end.
A study in India has found that the Delta strain, highly infectious and fast-spreading, drove the deadly second surge of COVID-19 in the country.
The Delta variant - or the B.1.617.2 strain - is 50 per cent "more infectious" than the Alpha variant, says the study by scientists of the Indian SARS COV2 Genomic Consortia and the National Centre for Disease Control.
But the scientists say there is no evidence of the role of the Delta variant in more deaths or greater severity of cases.
The Delta variant has played a bigger role in breakthrough infections or Covid infections after vaccination. There are no such cases when it comes to the Alpha variant, the study finds.
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.