Here’s what we know so far about the Delta variant. What is the Delta coronavirus variant? The B.1.617 lineage, identified in October, refers to several variants of the virus that causes Covid-19.
The most concerning of the lineage is the Delta or B.1.617.2 variant, which scientists say appears to have two advantages over earlier forms of the virus.
It has been established to be more infectious and it also appears to be more effective at evading vaccines, though people who are fully vaccinated still have significant protection against illness.
Are there any cases of this new variant in the U.S.? Yes. Almost 3,000 Delta cases have been reported in the U.S., according to the nonprofit Global Initiative on Sharing All Influenza Data, or