Driving this are two things: The large number of Americans who remain unvaccinated, and the rapid spread of the Delta variant. What the Delta variant isThe Delta variant, originally known as B.1.617.2, has been around since late last year but in recent months it has become speedily dominant in many countries. The Delta variant is more transmissibleHow much more is not really clear. One CDC document indicates the Delta variant is about as transmissible as chickenpox -- with each infected person infecting as many as eight or nine others, on average. "Testing identified the Delta variant in 90% of specimens from 133 patients," the researchers from the CDC and local health departments wrote in the CDC's weekly report.

Source: CNN July 30, 2021 14:36 UTC