CDC: Delta Variant Is Now 'Variant Of Concern'

The Delta variant, first identified in India, is more contagious and has spread to over 70 countries, including the US. It is responsible for a surge in cases in England, leading to a delay in reopening plans. Research indicates that two doses of the Pfizer and AstraZeneca vaccines are effective against this variant.

What percentage of new cases in the US is attributed to the Delta variant?

What do research findings indicate about the effectiveness of the Pfizer and AstraZeneca vaccines against the Delta variant?