A new study has revealed that mutations in the spike protein of the coronavirus, particularly D614G, makes the virus eight times more contagious than the wild-type virus.
This spike protein is used by the coronavirus to enter human cells and proliferate.
The research, published in the journal eLife, stated that D614G — one of several mutations in the variants that have emerged in the UK, South Africa, and Brazil, makes the coronavirus more infectious.
"The mutation has reached near-universal prevalence and is included in all current variants of concern," said Neville Sanjana, assistant professor of biology at New York University (NYU) in the US.
"Confirming that the mutation leads to more transmissibility may help explain, in part, why the virus has spread so rapidly over the past year," she added.
According to the authors of the study, the D614G mutation in the coronavirus spike protein likely emerged in early 2020. This is now the most prevalent and dominant form of the virus in many countries across the world.
For the study, the researchers introduced a virus with the D614G mutation into the human lung, liver, and colon cells. They also introduced the version of the virus without the mutation found early on in the pandemic into these same cell types for comparison.
The team observed that the D614G variant elevated the transmissibility of the virus up to eight-fold as compared to the original virus.
The researchers also found that the spike protein mutation made the virus more resistant to being split by other proteins.
This provides a possible mechanism for the variant's increased ability to infect cells, as the hardier variant resulted in a greater proportion of intact spike protein per virus, the researchers noted.
The researchers further speculated that the increased transmissibility of the D614G variant may influence Covid-19 vaccine development.