Scientists from the University of North Carolina have been studying the main mutation of the SARS-CoV-2 virus called D614G. As per the reports, this strain of the virus is more contagious as compared to the original one, which has emerged in Wuhan city of China. The D614G strain has been studied by many experts in the US and Europe before making its way back to Asia. Many studies have shown that mutation has made the virus more efficient in infecting cells; however, it is not very lethal. All these studies have taken place when the development of an effective vaccine has been underway. It is uncertain whether such a mutation will affect the efforts to find an effective vaccine. Well, the new study has found that mutation might make the vaccine more effective. The findings of the study have been released in Science magazine.
The D614G strain of the virus is a more dominant mutation at present. It has outgrown its ancestors by 10 fold. It can replicate more efficiently in primary nasal epithelial cells, which are the main sites for the person-to-person spread of the virus. This strain is more infectious because its spike protein is much efficient at latching on to cells, which makes a passage for infection. The D614G strain is more capable of replicating inside the cells than the original strain as well. However, during the study, experts have found an interesting action of this strain. This mutation forms a flap on the tip of the spike protein while it attaches to the ACE2 receptor present in the cells. This process grants more benefits to the virus for infecting cells. However, at the same time, it makes the virus more vulnerable to antibodies, which are present in the vaccine. These antibodies can take advantage of these flaps to prevent the spike protein from attaching to the cells. Antibodies in the vaccine can easily detect the signature of the spike protein and stop it from causing infection.
A team of different experts as well as developed a nasal spray, which takes the advantage of these flaps to neutralize the virus. Experts have studied the D614G strain via a simple experiment to prove that this mutated virus can spread more efficiently than the original strain. Scientists have infected two hamsters with the D614G strain and the original SARS-CoV-2 virus. They have kept eight healthy hamsters in cages next to infected ones. There has been a divider to block direct interaction between the animals. With this arrangement, the spread of the virus has been possible only through the air. After two days, 6 out of 8 hamsters have been infected with the D614G strain, whereas after four days, all of them have been infected with the mutated virus. There has been no case of the SARS-CoV-2 virus by the end of two days. Although after eight days, all of them have been infected with the original strain of the virus. The study has proved that the D614G strain spreads faster through the air than the original strain. Some experts do not support the stand that the virus is more contagious. They have said that some conclusions of the study might not be relevant to humans.