Tracking Changes in SARS-CoV-2 Spike: Evidence that D614G Increases Infectivity of the COVID- 19 Virus
Autor
Korber, Bette
Fischer, Will M.
Gnanakaran, Sandrasegaram
Yoon, Hyejin
Theiler, James
Abfalterer, Werner
Hengartner, Nick
Giorgi, Elena E.
Bhattacharya, Tanmoy
Foley, Brian
Hastie, Kathryn M.
Parker, Matthew D.
Partridge, David G.
Evans, Cariad M.
Freeman, Timothy M.
Silva, Thushan I. de
McDanal, Charlene
Perez, Lautaro G.
Tang, Haili
Moon-Walker, Alex
Whelan, Sean P.
LaBranche, Celia C.
Saphire, Erica O.
Montefior, David C.
Institución
Resumen
A SARS-CoV-2 variant carrying the Spike protein amino acid change D614G has become the most prevalent
form in the global pandemic. Dynamic tracking of variant frequencies revealed a recurrent pattern of G614
increase at multiple geographic levels: national, regional, and municipal. The shift occurred even in local epidemics where the original D614 form was well established prior to introduction of the G614 variant. The consistency of this pattern was highly statistically significant, suggesting that the G614 variant may have a fitness
advantage. We found that the G614 variant grows to a higher titer as pseudotyped virions. In infected individuals, G614 is associated with lower RT-PCR cycle thresholds, suggestive of higher upper respiratory tract
viral loads, but not with increased disease severity. These findings illuminate changes important for a mechanistic understanding of the virus and support continuing surveillance of Spike mutations to aid with development of immunological interventions.