A new study published in the journal Science reveals that a mutated strain of SARS-CoV-2, the virus that causes COVID-19, replicates faster than the original strain of the virus that spread at the beginning of the pandemic from China. The study found that the new virus strain, called D614G, which first emerged in Europe and has become the most prevalent strain in the world, is more transmissible because of the spike protein's greater ability to open cells so that the virus can enter them. Spike proteins are viral membrane proteins responsible for cell entry. However, the study also found that while the D614G strain spreads more quickly and replicates about 10 times faster than the original virus, it's also more sensitive to neutralization by antibody drugs and was not linked to more severe cases of the disease. "The D614G virus outcompetes and outgrows the ancestral strain by about 10-fold and replicates extremely efficiently in primary nasal epithelial cells, which are a potentially