Batch of homegrown coronavirus mutations seen in US

Batch of homegrown coronavirus mutations seen in US   Researchers said Sunday they have identified a batch of similar troubling mutations in coronavirus samples circulating in the United States. They've not only drawn attention to them; they've come up with a better shorthand for referring to them. They've named them after birds using labels such as Robin, Pelican and Bluebird.   The mutations all affect the same stretch of the spike protein -- the knob-like extension on the outside of the virus that it uses to dock onto the cells it infects, the researchers wrote in a pre-print report. It's not peer reviewed yet, but researchers are rushing such findings online to share them quickly with other experts.   The genetic stretch that is mutated, or changed, is called 677. The various changes are so similar that the researchers think evolution favors these particular variants. And it's in a troubling place, said Vaughn Cooper, director of the Center for Evolutionary Biology and Medicine at the University of Pittsburgh School of Medicine, who worked on the study.   "This stretch of Spike is important because of its proximity to a region key for virulence," Cooper told CNN via email.   "We actually think these mutations are relatively rare (compared to other types of mutation), but they are disproportionately selected when they occur," he added.   The team has been reviewing genomic sequences deposited into GISAID, a global database that researchers are using to share genetic information about the virus. It's where scientists first noticed the rise of troubling new variants such as B.1.1.7, first seen in the United Kingdom, and B.1.351, first seen in South Africa.