Delta

 NY Times: The Delta Variant: What Scientists Know - The variant is gaining traction worldwide. But vaccines are driving down coronavirus case numbers in the U.S., and it’s unclear whether Delta will reverse that trend. By Emily Anthes

Other evidence suggests that the variant may be able to partially evade the antibodies made by the body after a coronavirus infection or vaccination. And the variant may also render certain monoclonal antibody treatments less effective, the C.D.C. notes.