NEW REPORT on evolution of SARS-COV-2: The virus variant that's now widespread, D614G, replicates more efficiently in lab-grown human lung and airway cells. And when hamsters are infected with both versions, the new one has enhanced fitness & replicates better in upper airway 1/6 
The mutation is in the spike protein of the virus (the part that helps the virus grab onto, and infect cells.) Prior research took the spike protein and stuck it into other viruses that are easy to work with. And they showed the new spike mutation enhanced infection of cells 2/6
This study takes it a step farther. Researchers took the early SARS-CoV-2 strain and introduced the mutation right into the virus. So the two viruses are identical, except for a single amino acid change. So they confirmed that single mutation enhances the virus' capabilities 3/6
Other researchers found patients infected with the new variant have higher levels of the virus in their airways than those infected with the old version. But that wasn't associated w/ more severe disease. It is *possible* though that the new variant spreads more easily 4/6
Bad news: virus evolution *may* enhance ability to spread. Good news: vaccines, which are made against the old version, will likely work on new one. Prior study showed those immunized w/original spike protein vaccine neutralized the new spike just fine 5/6
And in this new study researchers found that sera from hamsters that were infected by the old version of the virus neutralized the new version even better. That's counterintuitive, but good news as far as vaccines go 6/6
Preprint: biorxiv.org/content/10.110…
Preprint: biorxiv.org/content/10.110…
