Egon Ozer, an infectious disease specialist at Northwestern University’s Feinberg School of Medicine, recently told The Washington Post that he noticed a mutation in the coronavirus samples he studied in Chicago. Although initially genetically identical to those that entered the United States from China, in May he discovered that 95 percent of the genomes he was sequencing had a “G” (short for glycine) at number 614 of their amino acids rather than a “D” (short for aspartic acid) for one of its amino acids, number 614.
Because the alteration occurred in the part of the genome that is responsible for the “spike protein” that gives the coronavirus its crown appearance, the mutation is significant. In fact, the spike proteins are responsible for the virus’s ability to invade human cells. “The increase is the trade part when it comes to viral entry,” said David Veesler, an assistant professor of biochemistry at the University of Washington School of Medicine, referring to previous research on coronavirus peak proteins.
As The Post noted, “Of the approximately 50,000 genomes of the new virus that researchers around the world have uploaded to a shared database, approximately 70 percent carry the mutation, officially designated D614G but more familiarly known to scientists as ‘G’ “.
Ozen was not alone observing this. A study by Scripps Research earlier this month had the same observation, and virologist Hyeryun Choe, PhD wrote that “Viruses with this mutation were much more infectious than viruses without the mutation in the cell culture system we used.” The study is still in peer review, so its authors emphasized that the conclusions should be considered preliminary. However, they noted that the impact of the mutation on the virus peaks “allows newly created viral particles to navigate the journey from the producer cell to the fully intact target cell, with less tendency to prematurely crumble.”
Salon contacted experts to reflect on what the mutation could mean.
“Of course, this is a normal process as viruses evolve,” Dr. Georges Benjamin, executive director of the American Public Health Association, told Salon by email. “It can affect the infectivity of the organism. There is still not much evidence that it has affected the severity. It can increase its ability to enter cells. (Therefore, more infectious but not necessarily more lethal). More infections can mean more people at risk, so theoretically you could see more diseases in people and if you had more high-risk people, then more serious disease. “
He added: “To date there is no evidence that it affects the ability to create an immune response from the spike protein. That said, only time will tell.”
Benjamin noted that there is no evidence that the mutation affects efforts to develop a vaccine, but added that “we always have to be on the lookout for the big genetic change that can mean we need a new or more effective vaccine. We get a flu shot every time each year due to relatively small changes in the influenza virus. A sufficient change in the SARS-2 virus may mean that we have to receive a new vaccine every year. Of course, that means we have a safe and effective vaccine to start “
Another expert echoed Benjamin’s views on the possible implications of the mutation.
“What we know today is that the SARS-CoV2 virus strain that contains the D614G mutation is occurring more frequently in patients with COVID-19,” said Dr. Russell Medford, president of the Center for Global Health Innovation and Coordination Global Health Crisis Center, he told Salon by email. “We also know that under highly controlled experimental conditions in the laboratory using harmless engineered viruses, that the D614G mutation confers functional properties on an important viral protein, S, which stabilizes the protein and improves the ability of the engineered virus to infect human cells in tissue culture. This suggests that increased infectivity may contribute to the increasing frequency of D614G SARS-CoV2 that we are seeing in patients with COVID-19. However, and most importantly, more research is needed as we do not know whether this mutation affects severity of symptoms in infected people or increases mortality
He added: “However, and most importantly, more research is needed as we do not know whether this mutation affects the severity of symptoms in infected people or increases mortality.”
Last month, a study by scientists at the Los Alamos National Laboratory raised the alarm that a mutated coronavirus strain could be so contagious that it worsens the ongoing pandemic.
“The Spike D614G mutation is a matter of urgent concern; it began to spread in Europe in early February, and when introduced into new regions it quickly became the dominant form. In addition, we present evidence of recombination between locally circulating strains, indicative of multiple strain infections, “the Los Alamos researchers wrote. “These findings [sic] they have important implications for SARS-CoV-2 transmission, pathogenesis, and immune interventions. “
They added that “D614G is increasing in frequency at an alarming rate, indicating a fitness advantage over the original Wuhan strain that allows for faster spread.”
