COVID-19's Mutation Is Even More Infectious

New and improved spike protein transmits easier than the coronavirus

Research in the journal Cell shows that a specific change in the SARS-CoV-2 coronavirus virus genome, previously associated with increased viral transmission and the spread of COVID-19, is more infectious in cell culture. The variant in question, D614G, makes a small but effective change in the virus’s ‘spike’ protein, which the virus uses to enter human cells.

“The D614G variant first came to our attention in early April, as we had observed a strikingly repetitive pattern,” says Bette Korber, a theoretical biologist at Los Alamos National Laboratory and lead author of the study. “All over the world, even when local epidemics had many cases of the original form circulating, soon after the D614G variant was introduced into a region it became the prevalent form."

Geographic information from samples from the GISAID COVID-19 viral sequence database show this shift in the viral population from the original form to the D614G variant occurred at every geographic level: country, subcountry, county, and city.

The SARS-CoV-2 virus has a low mutation rate overall (much lower than the viruses that cause influenza and HIV-AIDS). The D614G variant appears as part of a set of four linked mutations that appear to have arisen once and then moved together around the world as a consistent set of variations.

“These findings suggest that the newer form of the virus may be even more readily transmitted than the original form -- whether or not that conclusion is ultimately confirmed, it highlights the value of what were already good ideas: to wear masks and to maintain social distancing,” Dr. Korber says.

B. Korber, W.M. Fischer, S. Gnanakaran, et al. on behalf of theSheffield COVID-19 Genomics Group. Tracking changes in SARS-CoV-2 Spike: evidence that D614G increases infectivity of the COVID-19 virus. Cell, July 2, 2020; DOI: 10.1016/j.cell.20
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