• The SARS-CoV-2 strain now running rampant throughout the world is the most contagious mutation of SARS-CoV-2 
  • This mutation is also the dominant form of SARS-CoV-2
  • The mutation might make “individuals susceptible to a second infection”

American and British scientists have made the alarming discovery a virulent mutation of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the virus that causes COVID-19, is now the dominant strain worldwide. This mutation is far more contagious than the original coronavirus that came out of China in November 2019. It's also recombining with locally circulating strains to cause multiple strain infections.

These discoveries were detailed in a 33-page report, "Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2." The report was written by a team of researchers from the Los Alamos National Laboratory in New Mexico, Duke University in North Carolina and the Sheffield Teaching Hospitals NHS Foundation Trust in the United Kingdom.

It was posted on BioRxiv, a pre-print website where studies are shared before they are peer reviewed. The study is the first to document a mutation in SARS-CoV-2 that appears to make it more infectious, claims Dr. David Montefiori, a Duke University scientist who was part of the report team and who’s worked on an HIV vaccine for 30 years.

It identified this dominant SARS-CoV-2 strain as "D614G," and said it demands urgent attention from the world scientific community. The mutation began spreading in Europe in early February and quickly became the dominant form when introduced to new regions. D614G is responsible for the change in the virus’ protein spikes that allow SARS-CoV-2 to attach to human cells.

D614G is clearly doing something that gives it an evolutionary advantage over its predecessor and is fueling its rapid spread. Another scientist called D614G a “classic case of Darwinian evolution.”

“D614G is increasing in frequency at an alarming rate, indicating a fitness advantage relative to the original Wuhan strain that enables more rapid spread,” said the study.

Still unknown is if this mutant virus can account for regional variations in how hard COVID-19 is infecting different parts of the world.

“The story is worrying, as we see a mutated form of the virus very rapidly emerging, and over the month of March becoming the dominant pandemic form,” said study leader Dr. Bette Korber, a computational biologist at Los Alamos. “When viruses with this mutation enter a population, they rapidly begin to take over the local epidemic, thus they are more transmissible.”

An image taken with a scanning electron microscope  shows SARS-CoV-2 (yellow) — also known as 2019-nCoV, the virus that causes COVID-19
An image taken with a scanning electron microscope shows SARS-CoV-2 (yellow) — also known as 2019-nCoV, the virus that causes COVID-19 National Institutes of Health / Handout

The new strain’s dominance over its predecessors demonstrates higher infectiousness, though exactly why remains unknown. The study also identified 14 other Spike mutations. It warned mutations over time might confer the SARS-CoV-2 with selective advantages in transmission or resistance to clinical interventions.

The mutation might make “individuals susceptible to a second infection,” according to the study.

It’s possible D614G changes the spike in some way that helps the virus evade the immune system, believes Montefiori. “It is hypothetical. We are looking at it very hard.”