What we know about the Covid-19 Delta variant first found in India

The B.1.617.2 coronavirus strain (also known as the Delta variant), first first detected in India in February, has now gone global -- most recently detected in 74 countries. Just a month ago, it was only in 40 countries.   The strain is worrying health officials around the world, including in the US, where it now accounts for more than 6% of sequenced virus samples, the CDC says. That might seem a relatively small share, but the speed of its growth is worrying. A month ago, the strain accounted for just over 1% of sequenced virus samples, according to CDC data.   Experts believe the Delta variant sparked the huge wave in infections seen across India over the past two months. It is now causing concern in the United Kingdom, where it now comprises 91% of new cases, according to UK Health Secretary Matt Hancock.   Hancock said last weekend the strain is "around 40% more transmissible" than the formerly dominant Alpha variant. First detected in the UK, the Alpha variant was already more transmissible compared to the original strain of the virus.   Public Health England also says early evidence suggests the Delta variant may also cause an increased risk of hospitalization compared to the Alpha strain. While PHE cautioned that more data is needed, its early findings showed that people infected with the variant were more likely to suffer serious illness.   The good news is that data out of the UK indicates that the vaccines work against the variant. According to PHE, the Pfizer/BioNTech vaccine has been found to be 96% effective against hospitalization after two doses, while two doses of the Oxford-AstraZeneca vaccine have proven to be 92% effective against hospitalization.   And according to Public Health Scotland, two weeks after the second dose,  the Pfizer-BioNTech vaccine was found to be 79% protective against infection from the Delta variant, while the Oxford-AstraZeneca vaccine proved to be  60% effective against infection from the variant.